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摘要

综述了近年来3D打印在骨科中的应用和研究的几个层次:3D打印出用于术前模拟手术的模型, 可以形象直观地制定手术方案, 省去手术中多余的步骤, 减少手术时间和风险, 减轻医生的劳动强度;3D打印出基于计算机辅助设计、实现精准化手术的医疗导板和量身定做的植入物, 利用医疗导板可保证手术位置、方向及角度的准确性, 并提高手术的安全性和可预见性;个性化3D打印植入物能更好地满足患者的需要, 但在进入临床前仍面临政策上的挑战。与国外技术相比较, 我国在骨科3D打印方面还存在一定差距, 通过分析指明了我国需要着重发展的技术和对策。最后, 对3D打印在骨科上的应用进行了展望。

分享:
023384

摘要

立体光固化成型、选择性激光烧结和双光子聚合是具有代表性的激光微纳三维(3D)打印技术。其中双光子聚合的特征尺寸能够突破衍射极限, 使得在亚波长尺度上精密制造微光学元件成为可能。对这三种激光微纳3D打印技术进行了综述。

分享:
061430

摘要

现今各个应用领域的器件微型化、功能化和集成化的发展趋势, 对微纳加工技术提出了巨大挑战。越来越多器件的核心设计都依赖于高度图案化的三维复杂微纳结构。3D飞秒激光纳米打印(FsLNP)是一种无掩模的、利用飞秒激光直写进行加工的三维增材加工技术。其高度可设计性和远超光学衍射极限的高加工精度能够充分满足复杂技术需求。基于3D飞秒激光纳米打印独特的双光子聚合机制, 只要合理设计所需材料的光聚合方案和微纳结构, 可以制备一系列效率高且性能优越的微纳器件。简要介绍了3D飞秒激光纳米打印的技术要点、基本原理和目前所涉及的典型应用。

分享:
056449

摘要

简要介绍3D打印技术的原理, 以数字模型文件为基础, 运用可黏合材料, 通过逐层打印的方式构造物体。重点介绍3D打印玻璃的研究现状, 包括非激光式3D打印玻璃和激光式3D打印玻璃, 分析3D打印玻璃研究目前存在的问题。通过对原理与应用的详细介绍进一步加深对激光3D打印玻璃技术的认知。最后对激光3D打印玻璃技术进行了总结与展望。

分享:
022419

摘要

近年来, 激光在增材制造技术中的应用丰富了增材制造技术类别, 拓宽了精度范围和应用领域。概括了激光增材制造(LAM)陶瓷材料技术的类别、原理和特点, 介绍了其应用和研究现状。另外, 分析了各种技术存在的不足, 并对陶瓷材料的LAM的发展前景进行了展望。

分享:
026350

摘要

随着激光增材制造金属件的质量和性能的提高, 金属粉体材料已成为金属激光增材制造技术应用的制约因素, 激光增材制造专用金属粉体材料成为了近年来的研究热点之一。针对激光增材制造钢粉体材料, 从材料设计、粉体制备、表征评价、样件实例等方面综述了激光增材制造钢粉体材料的国内研究现状, 提出了激光3D粉体材料研究和应用中存在的主要问题及发展方向。

分享:
016314

摘要

总结了增材制造技术在个性化眼科医疗、精准眼科医疗、移动眼科医疗、眼视光学和眼科仿生领域的近期应用与未来发展前景。激光增材制造技术凭借易于定制和高效率的优势, 有望令病人获得更具人性化、更有针对性、更加普及化的眼科医疗服务。

分享:
017204

摘要

介绍了铝合金增材制造的相关技术研究进展。着重阐述了选区激光熔化、电弧填丝增材制造、激光-电弧复合增材制造在铝合金增材制造领域的优势与发展前景。研究结果表明, 选区激光熔化的研究主要集中在成形件致密度的改善、微观组织控制和力学性能提升等方面, 现阶段的成形件的致密度已接近100%, 微观组织和力学性能优于铸件的但差于锻件的;电弧填丝增材制造的研究主要集中在大型结构的尺寸控制, 但较大的热输入量限制了成形结构的性能提升;激光-电弧复合铝合金增材制造的相关研究较少, 完善相应的工艺技术及激光与电弧的耦合行为是其发展方向。

分享:
047235

摘要

激光选区熔化(SLM)能够实现由粉末到零件的自由制造, 成形件尺寸精度高、表面粗糙度低, 特别适合具有复杂结构的模具的成形。重点介绍了SLM成形模具钢的研究现状、成形材料、工艺特点、组织演变和性能优化等, 并简要介绍了其应用现状,如随形冷却流道的应用案例等。总结了现阶段SLM成形模具钢存在的问题, 并对其未来的研究方向进行了展望与探讨。

分享:
035199

摘要

激光选区熔化(SLM)作为一种直接制造金属构件的增材制造技术, 可实现复杂结构件的高精度制造。介绍了SLM技术的发展现状及原理, 从材料体系、成形工艺、显微组织及力学性能方面论述了国内外钛及钛合金SLM技术的研究及应用现状, 总结了SLM技术加工钛及钛合金过程中存在的问题,及对其未来的发展趋势进行了展望。

分享:
030215

摘要

随着轻量化、结构功能一体化的强劲需求, 高强铝合金复杂精密零件在航天航空等领域应用广泛, 但因其焊接性能和铸造性能差, 传统加工方法难以制备。激光选区熔化成形(SLM)技术是制备该类零件的最有前景的新方法。高强铝合金对激光吸收率低、热导率高、易氧化、含大量易烧损合金元素, 有很强的热裂倾向, 成形难度极大, 因此目前其SLM成形技术远落后于其他材料。但是由于其广阔的应用前景, 近几年发展迅速。总结了国内外高强铝合金激光选区熔化成形的研究现状、发展趋势及存在的主要问题。

分享:
040284

摘要

激光选区熔化(SLM)是利用高能量激光束将设计好的二维截面上的金属合金粉末熔化, 由下而上逐层打印实体零件的一种金属增材制造(AM)技术,具有尺寸精度高、表面质量好、致密度高和材料浪费少的优势, 已经成为AM技术在金属零件成型领域中的重要技术之一。阐述了SLM技术的原理和研究现状, 总结了其在航空航天、医学、汽车、模具等方面的应用现状, 并展望了其未来的发展趋势。

分享:
055314

摘要

提出了一种分布式光纤振动和温度传感系统。该系统在双马赫-曾德尔干涉仪分布式振动传感系统的框架上, 采用波分复用的方法在一条传感臂上耦合两种波长的光, 并行实现了基于激光干涉的分布式光纤振动传感和基于拉曼背向散射的分布式温度传感, 从而达到了振动和温度双物理量的同时探测。该方法有效利用了双马赫-曾德尔干涉仪的传感光纤, 在实验中实现了10 km长度上振动和温度双物理量的同时探测, 振动传感的定位误差为±30 m, 温度传感的空间分辨率和温度精度分别为1 m和±1.8 ℃。该系统的优点是将激光干涉和拉曼背向散射有效结合, 实现了复杂环境中对振动和温度同时探测的需求, 并有效利用了传感光纤, 具有重要的实际意义和经济价值。

PDF全文中国激光 | 2018,45(01):0110002
分享:
024244

摘要

基于混沌同步, 构建安全性增强的双向长距离混沌保密通信系统。结果表明:在合适的双混沌光注入参数下, 驱动激光器(DL)可以产生低时延特征(TDS)、宽带宽的混沌信号; DL输出的混沌信号注入到2个响应激光器(RLs)中, 通过优化注入参数, 2个RLs可输出TDS更低、带宽更宽的混沌信号, 且2个混沌信号在实现高质量混沌同步的同时与DL输出混沌保持极低的相关系数(小于0.1); 基于2个RLs之间高质量的混沌同步, 可实现安全性增强的双向远距离混沌保密通信。采用色散位移光纤作为传输信道, 20 Gbit/s的信息在传输120 km后, 解调信息的Q因子大于6; 而采用普通单模光纤作为传输信道, 1 Gbit/s的信息在传输140 km后, 解调信息的Q因子大于8。

PDF全文中国激光 | 2018,45(01):0106001
分享:
043160

摘要

为满足现代工业各领域对高精度、大测量范围、实时性测量的要求, 提出一种高精度激光追踪测量方法, 来实现对随动目标的精密追踪测量。基于四象限探测器的激光追踪测量系统可实时地测量入射激光光斑相对于四象限探测器中心的偏移量, 利用响应速度快的伺服电机、可编程多轴运动控制器(PMAC)的运动控制卡构建闭环控制系统, 实现高精度快速激光追踪测量。实验结果表明, 所提出的高精度激光追踪测量方法实时性好、测量精度高; 当在激光光斑距离四象限探测器中心±1000 μm范围内追踪测量时, 光斑偏移量误差为31.2 μm, 激光光斑返回四象限探测器中心的平均时间为0.259 ms。

PDF全文中国激光 | 2018,45(01):0104003
分享:
035246

摘要

提出一种基于高斯脉冲激光空间分辨测量光学元件表面激光损伤阈值的方法。通过设定激光能量密度差对高斯光斑进行能量密度分区, 统计并分析每个能量密度分区的能量密度以及损伤密度分布, 设定一个零损伤密度所对应的激光能量密度作为所测样品的激光损伤阈值。同时利用国际标准1-on-1激光损伤阈值测试方法对同一样品进行激光损伤阈值测试, 并将两种测试方法获得的损伤阈值进行了比较分析, 证明基于高斯脉冲激光空间分辨的激光损伤阈值测试方法, 解决了国际标准1-on-1激光损伤阈值测试中将高斯光斑内空间能量密度以及损伤点的不均匀分布等效地视作均匀分布所带来的问题。

PDF全文中国激光 | 2018,45(01):0104002
分享:
022197

摘要

利用超音速激光沉积技术在316L基体上制备了WC/SS316L复合沉积层, 并分析了该复合沉积层中颗粒的沉积行为、界面结合、组织结构特征以及其在电化学环境下的失效机理。研究结果表明, 由于激光辐照的软化作用, SS316L颗粒在高速撞击过程中表现出较好的塑性变形能力, 能够实现有效沉积; 在激光辐照和高速粒子塑性变形的双重作用下, 超音速激光沉积层较单一冷喷(CS)沉积层具有更好的界面结合行为。由于高速粒子塑性变形产生了加工硬化现象, 沉积层中SS316L的显微硬度较原始粉末的明显增大。在电化学腐蚀环境下, WC/SS316L界面较易发生腐蚀行为。

PDF全文中国激光 | 2018,45(01):0102001
分享:
012165

摘要

详细讨论了直接液体冷却薄片激光器的设计。包括增益模块中晶体和冷却液的选取, 以及流道结构的设计, 分析了增益模块中两类组合方式各自的优缺点。组合方式一中, 需要严格控制激光的入射角以及晶体的切割角, 给出了具体的计算和分析。组合方式二无需特别选取角度, 然而所选的冷却液的折射率要与晶体的折射率尽可能一致。在抽运方式选取方面, 分析了采用端面抽运和侧面抽运对激光器储能以及像差等方面的影响。最终, 理论分析了采用10片Nd∶YLF作为增益介质, 折射率匹配液作为冷却液, 在抽运功率为5 kW时, 激光器输出功率大于1 kW, 光-光效率大于20%, 理论分析和实验结果基本一致。

PDF全文中国激光 | 2018,45(01):0101012
分享:
031194

摘要

报道了一种室温条件下工作的高功率激光二极管(LD)端面抽运Yb∶YAG板条双波长激光放大器, 稳定的双波长运转在1029.6, 1031.5 nm。基于Yb∶YAG宽带荧光特性, 建立了双波长放大模型, 通过数值模拟研究了不同抽运条件下激光光谱放大输出特性。通过940 nm激光二极管双端抽运Yb∶YAG晶体, 拥有双波长光谱的种子光从晶体一端注入并进行放大。实验结果表明,在1.18 kW注入时获得了6.56 kW的双波长连续激光输出, 与数值模拟结果相吻合。双波长激光放大理论和实验研究为进一步实现高功率光谱合成等应用奠定了基础。

PDF全文中国激光 | 2018,45(01):0101006
分享:
012149

摘要

理论分析了影响二极管端面抽运Nd∶YAG板条激光放大器放大效率的因素, 设计了主振荡功率放大板条连续激光器。使用1064 nm窄线宽光纤激光器作为种子源, 采用两个Nd∶YAG板条激光放大器先串接再双程放大的技术路线。两个Nd∶YAG板条激光放大器的尺寸结构完全相同, Nd∶YAG板条的尺寸均为150.2 mm×2.5 mm×30 mm, 每个板条都是半导体激光器阵列双端抽运。放大器抽运源总功率为21.6 kW时, 实现了5.4 kW连续激光的输出, 光-光转换效率为24.8%, 光束质量β为3.5。在输出光路位置使用狭缝空间滤波器, 光束质量β可以提升到2.5。

PDF全文中国激光 | 2018,45(01):0101003
分享:
027190

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摘要

Q-switched operation of an Nd:LuAG laser using gold nanorods (GNRs) as the saturable absorber (SA) is reported, which also produces the highest average power among the nanosecond Nd-doped Q-switched lasers by GNRs-based SA. The applied GNRs are prepared using a seed-mediated growth method and then dropped onto the quartz substrate to fabricate the SA. The average power of the Q-switched laser is 516 mW with the shortest pulse duration of 606.7 ns and the repetition rate of 265.1 kHz.

    PDF全文Chinese Optics Letters | 2018,16(02):020011
    分享:
    046219

    摘要

    We demonstrate a dual-wavelength passively Q-switched Nd3+-doped glass fiber laser using a few-layer topological insulator Bi2Se3 as a saturable absorber (SA) for the first time, to the best of our knowledge. The laser resonator is a simple and compact linear cavity using two fiber end-facet mirrors. The SA is fabricated by Bi2Se3/polyvinyl alcohol composite film. By inserting the SA into the laser cavity, a stable Q-switching operation is achieved with the shortest pulse width and maximum pulse repetition rate of 601 ns and 205.2 kHz, respectively. The maximum average output power and maximum pulse energy obtained are about 6.6 mW and 38.8 nJ, respectively.

      PDF全文Chinese Optics Letters | 2018,16(02):020016
      分享:
      038218

      摘要

      We report the fabrication of an MoS2 black phosphorus (BP) composite saturable absorber by liquid phase exfoliation and the spin-coating method and further exploitation to build a 2 μm passively Q-switched Tm:YAP laser. Such a composite based Q-switched laser with a duration of 488 ns and corresponding peak power of 85.9 W is obtained, which shows an improved saturable absorption effect than that of single MoS2 (616 ns, 68.7 W) and BP (932 ns, 22.4 W). The results indicate that simple and reasonable fabrication of the vertical composite from two-dimensional atomic layer materials opens up the possibility to create an unprecedented saturable absorber with exciting properties.

        PDF全文Chinese Optics Letters | 2018,16(02):020018
        分享:
        038209

        摘要

        Using a novel silver nanorods absorber with a localized surface plasmon resonance absorption peak at 1.06 μm, we obtain a diode-pumped passively Q-switched (PQS) Nd,Gd:CaF2 disordered crystal laser output. Its PQS pulse laser performances are studied comprehensively and systematically in this Letter. The single pulse energy and peak power can be attained to 2.15 μJ and 2.06 W, respectively.

          PDF全文Chinese Optics Letters | 2018,16(02):020015
          分享:
          035188

          摘要

          The simultaneous dual-band pulsed amplification is demonstrated from an Er/Yb co-doped fiber (EYDF), and consequently a high-power all-fiber single-mode 1.0/1.5 μm dual-band pulsed master oscillator power amplifier (MOPA) laser source is realized for the first time, to the best of our knowledge, based on one singlegain fiber. The simultaneous outputs at 1061 and 1548 nm of the laser source have the maximum powers of 10.7 and 25.8 W with the pulse widths of 9.5 ps and 2 ns and the pulse repetition rates of 178 and 25 MHz, respectively. This EYDF MOPA laser source is seeded by two separate preamplifier chains operating at 1.0 and 1.5 μm wavebands. The dependence of the laser output powers on the length of the large-mode area EYDF, the ratio of the powers of the two signals launched into the booster amplifier, and the wavelength of the 1 μm seed signal are also investigated experimentally.

            PDF全文Chinese Optics Letters | 2018,16(02):020010
            分享:
            052192

            摘要

            The direct generation of passively Q-switched lasers at a green wavelength has rarely been investigated in the past. In this Letter, we demonstrate a passively Q-switched praseodymium-doped yttrium lithium fluoride green laser at 522 nm using CdTe/CdS quantum dots as a saturable absorber. A maximum average output power of 33.6 mW is achieved with the shortest pulse width of 840 ns. The corresponding pulse energy and peak power reached 0.18 μJ and 0.21 W, respectively. To the best of our knowledge, this is the first demonstration in regard to a quantum dots saturable absorber operating in the green spectral region.

              PDF全文Chinese Optics Letters | 2018,16(02):020005
              分享:
              036103

              摘要

              Black phosphorus (BP) is a promising material for ultrafast and broadband photodetection because of its narrow bandgap from 0.35 eV (bulk) to 1.8 eV (monolayer) and high carrier mobility. Although photodetectors based on BP with different configurations have been reported, high photosensitivity was mostly observed in the visible range. A highly efficient BP-based infrared photodetector operated in the telecom spectral range, especially at 1550 nm, has not been demonstrated. Here, we report a Schottky-type photodetector based on thin BP flakes, operating in a broad spectral range from visible (635 nm) to infrared (1550 nm). A responsivity as high as 230 A·W?1 was achieved at 1550 nm with a source-drain bias of 1 V. The rise time is 4.8 ms, and the fall time is 6.8 ms. Under light illumination and external bias, the Schottky barrier between the BP and metal was reduced, leading to efficient photocurrent extraction. The unprecedented performance of the BP photodetector indicates intriguing potential for sensing, imaging, and optical communication.

                PDF全文Chinese Optics Letters | 2018,16(02):020002
                分享:
                079151

                摘要

                We propose and demonstrate a passively harmonic mode-locked erbium-doped fiber laser (EDFL) using carbon nanotubes polyvinyl alcohol (CNTs-PVA) film. The laser allows generation of the pulses with a repetition rate of 580 MHz, which corresponds to the 22nd harmonics of a 26.3 MHz fundamental repetition rate under 323 mW pump power. A particularly noteworthy feature of the pulses is the super-mode suppression ratio (SMSR), which is over 40 dB, indicating a stable operation.

                  PDF全文Chinese Optics Letters | 2018,16(02):020019
                  分享:
                  033102

                  摘要

                  High-power ultrafast fiber lasers operating at the 2 μm wavelength are extremely desirable for material processing, laser surgery, and nonlinear optics. Here we fabricated large-core (LC) double-cladding Tm-doped silica fiber via the sol-gel method. The sol-gel-fabricated Tm-doped silica (SGTS) fiber had a large core diameter of 30 μm with a high refractive index homogeneity (Δn=2×10?4). With the newly developed LC SGTS fiber as the gain fiber, high-power mode-locking was realized. By using a semiconductor saturable absorber mirror (SESAM) as a mode locker, the LC SGTS fiber oscillator generated mode-locked pulses with an average output power as high as 1.0 W and a pulse duration of 23.9 ps at the wavelength of 1955.0 nm. Our research results show that the self-developed LC Tm-doped silica fiber via the sol-gel method is a promising gain fiber for generating high-power ultrafast lasers in the 2 μm spectral region.

                    PDF全文Chinese Optics Letters | 2018,16(02):020020
                    分享:
                    03993

                    摘要

                    A diode-pumped Tm:YLF passively Q-switched laser at 2 μm was first demonstrated by using graphene oxide (GO) as a saturable absorber (SA). In this letter, continuous-wave (CW) laser and pulse laser performances were studied meticulously and systematically. It reasonably showed the dependence of the pulse duration, pulse energy, and pulse repetition rate on the absorbed power. A maximum repetition rate of 38.33 kHz and a single pulse energy of 9.89 μJ were obtained.

                      PDF全文Chinese Optics Letters | 2018,16(02):020013
                      分享:
                      031108

                      摘要

                      A highly stable Q-switched laser incorporating a mechanically exfoliated tungsten sulphoselenide (WSSe) thin sheet saturable absorber (SA) is proposed and demonstrated. The SA assembly, formed by sandwiching a thin WSSe sheet between two fiber ferrules within the erbium-doped fiber laser, is used to effectively modulate the laser cavity losses. The WSSe-based SA has a saturation intensity of ~0.006 MW/cm2 and a modulation depth of 7.8%, giving an optimum Q-switched laser output with a maximum repetition rate of 61.81 kHz and a minimum pulse width of 2.6 μs. The laser’s highest output power of 0.45 mW and highest pulse energy of 7.31 nJ are achieved at the maximum pump power of 280.5 mW. The tunability of the cavity’s output at the maximum pump power is analyzed with a C-band tunable bandpass filter, giving a broad tunable range of ~40 nm, from 1530 nm to 1570 nm. The output performance of the tunable Q-switched laser correlates well with the gain spectrum of erbium-doped fibers, with the shift in the gain profile as a result of the saturated SA.

                        PDF全文Chinese Optics Letters | 2018,16(02):020009
                        分享:
                        042103

                        摘要

                        The all-optical approach plays an important role in ultrafast all-optical signal processing, and the all-fiber scheme has a wide application in optical communications. In this letter, we investigate an all-optical modulator using few-layer molybdenum disulfide (MoS2)-polyvinyl alcohol (PVA) thin films based on the thermo-optic effect and obtain a long-time stable modulated output by applying polarization interference. By absorbing the injected 980 nm pump (control light), MoS2 generates heat, changes the refractive index of MoS2, and modulates the polarization of light. The obtained thermal all-optical modulator has a rise time of 526 μs.

                          PDF全文Chinese Optics Letters | 2018,16(02):020003
                          分享:
                          053130

                          摘要

                          As the typical material of two-dimensional transition metal dichalcogenides (TMDs), few-layered MoS2 possesses broadband saturable absorption and a large nonlinear refractive index, which could be regarded as a promising candidate for dual-function photonic device fabrication. In this work, the coexistence of a bound soliton and harmonic mode-locking soliton was demonstrated in an ultrafast fiber laser based on a MoS2-deposited microfiber photonic device. Through a band-pass filter, each multi-soliton state was investigated separately. The bound soliton has periodic spectral modulation of 1.55 nm with a corresponding pulse separation of 5.16 ps. The harmonic mode-locking soliton has the repetition rate of 479 MHz, corresponding to the 65th harmonic of the fundamental repetition rate. The results indicated that there exist more possibilities of different multi-soliton composites, which would enhance our understanding of multi-soliton dynamics.

                            PDF全文Chinese Optics Letters | 2018,16(02):020008
                            分享:
                            035111

                            摘要

                            Initiated by graphene, two-dimensional (2D) layered materials have attracted much attention owing to their novel layer-number-dependent physical and chemical properties. To fully utilize those properties, a fast and accurate determination of their layer number is the priority. Compared with conventional structural characterization tools, including atomic force microscopy, scanning electron microscopy, and transmission electron microscopy, the optical characterization methods such as optical contrast, Raman spectroscopy, photoluminescence, multiphoton imaging, and hyperspectral imaging have the distinctive advantages of a high-throughput and nondestructive examination. Here, taking the most studied 2D materials like graphene, MoS2, and black phosphorus as examples, we summarize the principles and applications of those optical characterization methods. The comparison of those methods may help us to select proper ones in a cost-effective way.

                              PDF全文Chinese Optics Letters | 2018,16(02):020006
                              分享:
                              043110

                              摘要

                              The potential of bulk-like WTe2 particles for the realization of a passive Q-switch operating at the 1 μm wavelength was investigated. The WTe2 particles were prepared using a simple mechanical exfoliation method together with Scotch tape. By attaching bulk-like WTe2 particles, which remained on the top of the sticky surface of a small segment of the Scotch tape, to the flat side of a side-polished fiber, a saturable absorber (SA) was readily implemented. A strong saturable absorption was then readily obtained through an evanescent field interaction with the WTe2 particles. The modulation depth of the prepared SA was measured as ~2.18% at 1.03 μm. By incorporating the proposed SA into an all-fiberized ytterbium-doped fiber ring cavity, stable Q-switched pulses were readily achieved.

                                PDF全文Chinese Optics Letters | 2018,16(02):020017
                                分享:
                                03895

                                摘要

                                We have prepared the graphene/MoS2 heterostructure by a hydrothermal method, and presented its nonlinear absorption parameters and application as a nonlinear optical modulator in the mid-infrared region. Using the nonlinear optical modulator, stable passively Q-switched operation of an Er3+-doped ZrF4-BaF2-LaF3-AlF3-NaF (ZBLAN) fiber laser at ~2.8 ?μm can be obtained. The Q-switched Er3+-doped ZBLAN fiber laser can yield per-pulse energy up to 2.2 μJ with the corresponding pulse width and pulse repetition rate of 1.9 μs and 45 kHz, respectively. Our results indicate that the graphene/MoS2 heterostructure can be a robust optical modulator for pulsed lasers in the mid-infrared spectral range.

                                  PDF全文Chinese Optics Letters | 2018,16(02):020012
                                  分享:
                                  03099

                                  摘要

                                  Materials in the transition metal dichalcogenide family, including WS2, MoS2, WSe2, and MoSe2, etc., have captured a substantial amount of attention due to their remarkable nonlinearities and optoelectronic properties. Compared with WS2 and MoS2, the monolayered MoTe2 owns a smaller direct bandgap of 1.1 eV. It is beneficial for the applications in broadband absorption. In this letter, using the magnetron sputtering technique, MoTe2 is deposited on the surface of the tapered fiber to be assembled into the saturable absorber. We first implement the MoTe2-based Q-switched fiber laser operating at the wavelength of 1559 nm. The minimum pulse duration and signal-to-noise ratio are 677 ns and 63 dB, respectively. Moreover, the output power of 25 mW is impressive compared with previous work. We believe that MoTe2 is a promising 2D material for ultrafast photonic devices in the high-power Q-switched fiber lasers.

                                    PDF全文Chinese Optics Letters | 2018,16(02):020007
                                    分享:
                                    037109

                                    摘要

                                    Faraday effect measurements of holmium oxide (Ho2O3) ceramics-based magneto-optical materials, highly potential material candidates for high-energy laser Faraday isolators, are presented in this paper. Temperature dependence of the Verdet constant of nondoped Ho2O3 ceramics was measured for temperatures 15–305 K at $1.064~\unicode[STIX]{x03BC}\text{m}$ wavelength. The Verdet constant dispersion for wavelengths 0.5–$1~\unicode[STIX]{x03BC}\text{m}$ and $1.064~\unicode[STIX]{x03BC}\text{m}$ was measured for both nondoped Ho2O3 ceramics and Ho2O3 ceramics doped with terbium Tb3+ (0.2 at. %) and cerium Ce3+ (0.1 at. %) ions. The results suggest that the relatively low level of doping of Ho2O3 with these ions has no significant boosting impact on the Faraday effect. Therefore, other compositions of Ho2O3 ceramics-based magneto-optical materials, as well as various doping concentrations, should be further examined.

                                      分享:
                                      041114

                                      摘要

                                      The effect of material dispersion on the optical properties of one-dimensional non-Hermitian scattering systems is investigated in detail. In particular, multilayer heterostructures with gain and loss (parity-time symmetric or not) are examined by taking into account the dispersion of each layer. The exceptional points and phase transitions are characterized based on the spectrum of the corresponding scattering matrix. We demonstrate that an on-average lossy heterostructure can amplify an incident plane wave in the frequency range associated with the emission frequency of the layer with gain.

                                        PDF全文Photonics Research | 2018,6(04):A1-A5
                                        分享:
                                        0077

                                        摘要

                                        The ability to manipulate the valence state conversion of rare-earth ions is crucial for their applications in color displays, optoelectronic devices, laser sources, and optical memory. The conventional femtosecond laser pulse has been shown to be a well-established tool for realizing the valence state conversion of rare-earth ions, although the valence state conversion efficiency is relatively low. Here, we first propose a femtosecond laser pulse shaping technique for improving the valence state conversion efficiency of rare-earth ions. Our experimental results demonstrate that the photoreduction efficiency from Sm3+ to Sm2+ in Sm3+-doped sodium aluminoborate glass using a π phase step modulation can be comparable to that using a transform-limited femtosecond laser field, while the peak laser intensity is decreased by about 63%, which is very beneficial for improving the valence state conversion efficiency under the laser-induced damage threshold of the glass sample. Furthermore, we also theoretically develop a (2+1) resonance-mediated three-photon absorption model to explain the modulation of the photoreduction efficiency from Sm3+ to Sm2+ under the π-shaped femtosecond laser field.

                                          PDF全文Photonics Research | 2018,6(02):144-148
                                          分享:
                                          02891

                                          查看更多

                                          摘要

                                          We investigate the on-line writing identical fiber Bragg grating (FBG) arrays using the phase mask technique. Given the limitation of laser power, the energy density uniformity and the horizontal width of the writing spot cannot be further optimized. The results show that the FBG arrays obtained in the optimal process (drawing speed of 12 +(-) 0.15 m/min and average tension of 38.2 g) have a central wavelength bandwidth of less than 0.1 nm and an average reflectivity of 0.26%. Thus, the phase mask method is a promising alternative for on-line writing identical FBG arrays.

                                            PDF全文Chinese Optics Letters | 2013,11(03):030602
                                            分享:
                                            09691561

                                            摘要

                                            A non-adiabatic microfiber coupler is fabricated by flame brushing technique and then theoretically and experimentally analyzed. The effective length of the microfiber coupler is determined by simulation, and a low-noise laser is demonstrated using various lengths of erbium-doped fiber (EDF) when incorporated in a laser setup. At 18.6-mW input pump power, the maximum output power of 20 \mu W and the lowest lasing threshold of 3.8 mW are obtained with a 90-cm-long EDF.

                                              PDF全文Chinese Optics Letters | 2014,12(02):021403
                                              分享:
                                              06452537

                                              摘要

                                              We propose a simple and low-cost Fabry-Perot (F-P) fiber sensor based on an inner air cavity. The air cavity is fabricated at the fiber-tip by splicing a single-mode fiber and a hollow-core photonic crystal fiber (HC-PCF), with un-collapsed section of the HC-PCF being cleaved. Application of F-P fiber-tip sensor in the external refractive index (RI) measurement is experimentally demonstrated. The sensor exhibits a good linear response and high sensitivity of -54.409 dB/RIU in the RI range of 1.333–1.413. Therefore, it is applied to fiber-optic biological and chemical sensing.

                                                PDF全文Chinese Optics Letters | 2014,12(s1):S11202
                                                分享:
                                                05341059

                                                摘要

                                                We present photonics technology based on a bulk-Si substrate for cost-sensitive dynamic random-access memory (DRAM) optical interface application. We summarize the progress on passive and active photonic devices using a local-crystallized Si waveguide fabricated by solid phase epitaxy or laser-induced epitaxial growth on bulk-Si substrate. The process of integration of a photonic integrated circuit (IC) with an electronic IC is demonstrated using a 65 nm DRAM periphery process on 300 mm wafers to prove the possibility of seamless integration with various complementary metal-oxide-semiconductor devices. Using the bulk-Si photonic devices, we show the feasibility of high-speed multidrop interface: the Mach–Zehnder interferometer modulators and commercial photodetectors are used to demonstrate four-drop link operation at 10 Gb/s, and the transceiver chips with photonic die and electronic die work for the DDR3 DRAM interface at 1.6 Gb/s under a 1∶4 multidrop configuration.

                                                  PDF全文Photonics Research | 2014,2(03):A25-A33
                                                  分享:
                                                  0395877

                                                  摘要

                                                  The Z-backlighter laser facility primarily consists of two high energy, high-power laser systems. Z-Beamlet laser (ZBL) (Rambo et al., Appl. Opt. 44, 2421 (2005)) is a multi-kJ-class, nanosecond laser operating at 1054 nm which is frequency doubled to 527 nm in order to provide x-ray backlighting of high energy density events on the Z-machine. Z-Petawatt (ZPW) (Schwarz et al., J. Phys.: Conf. Ser. 112, 032020 (2008)) is a petawatt-class system operating at 1054 nm delivering up to 500 J in 500 fs for backlighting and various short-pulse laser experiments (see also Figure 10 for a facility overview).With the development of the magnetized liner inertial fusion (MagLIF) concept on the Z-machine, the primary backlighting missions of ZBL and ZPW have been adjusted accordingly. As a result, we have focused our recent efforts on increasing the output energy of ZBL from 2 to 4 kJ at 527 nm by modifying the fiber front end to now include extra bandwidth (for stimulated Brillouin scattering suppression). The MagLIF concept requires a well-defined/behaved beam for interaction with the pressurized fuel. Hence we have made great efforts to implement an adaptive optics system on ZBL and have explored the use of phase plates. We are also exploring concepts to use ZPW as a backlighter for ZBL driven MagLIF experiments. Alternatively, ZPW could be used as an additional fusion fuel pre-heater or as a temporally flexible high energy pre-pulse. All of these concepts require the ability to operate the ZPW in a nanosecond long-pulse mode, in which the beam can co-propagate with ZBL. Some of the proposed modifications are complete and most of them are well on their way.

                                                  分享:
                                                  0338570

                                                  摘要

                                                  合成孔径激光雷达(SAL)能够突破激光的衍射限制, 满足对远距离目标和场景进行高精度实时成像的需求。从SAL理论和实验进展两方面, 详细总结分析了SAL的国内外发展现状。在此基础上, 总结和分析了实现SAL实际应用, 还需深入研究的几个关键技术: 激光光源、发射信号波形、探测体制、激光传输特性和目标反射特性、成像算法和运动补偿等, 为进行SAL的深入研究和实用化奠定基础。

                                                  分享:
                                                  1332734

                                                  摘要

                                                  By considering the cross phase modulation (XPM) between the two orthogonal poparization components, the nonlinear birefringence and nonlinear polarization evolution (NPE) in highly-nonlinear fiber (HNLF), as well as the unequal evolutions of the state of polarization (SOP) between the clockwise (CW) and counter-clockwise (CCW) waves in a nonlinear amplifying loop mirror (NALM) are analyzed. It is pointed out that the traditional cosine expression is no longer valid for the power transmission of NALM due to uncompleted interference under the high power condition. The analytical expression considering NPE effect is derived, and the experimental result is presented.

                                                    分享:
                                                    13173930

                                                    摘要

                                                    The biochemical composition of atherosclerotic plaques is closely related to plaque stability and, therefore, to the associated risk of plaque evolution and rupture. Combinations of current imaging modalities, such as optical coherence tomography (OCT) with spectroscopic methods, therefore offer the possibility of concurrently obtaining morphological as well as chemical information. Raman spectroscopy is one of the most promising techniques that can be combined with intravascular imaging modalities. A microscopy setup merging both techniques has been applied to characterize plaque depositions of a human aorta affected by the disease. Calcified depositions were clearly identified and subsequently confirmed by histopathology.

                                                      PDF全文Chinese Optics Letters | 2017,15(09):090008
                                                      分享:
                                                      0195397

                                                      摘要

                                                      Aiming to overcome the low converging rate and susceptibility to the environment in focusing the coherent light through the turbid medium, four-element division algorithm (FEDA) optimization is proposed. Full levels of comparisons with the currently employed element-based algorithms, stepwise sequential algorithm (SSA), and continuous sequential algorithm (CSA) show that FEDA only takes one third of the measurement time to find the optimized solution, which means that FEDA is promising in practical applications, such as for deep tissue imaging.

                                                        PDF全文Chinese Optics Letters | 2017,15(10):102901
                                                        分享:
                                                        0188355

                                                        摘要

                                                        合成孔径激光雷达(Synthetic Aperture Ladar,SAL)是一种高分辨率成像激光雷达,是微波合成孔径雷达(Synthetic Aperture Radar,SAR)技术在光学波段的推广。理论上,SAL的成像分辨率能够突破真实光学口径衍射极限、与目标距离无关,对成百上千公里距离上的目标,可以达到厘米级。这种卓越的成像能力,使SAL有望发展成为远程高分辨率成像观测新工具,补充现有光学成像设备之不足,在地基、空基或天基等平台中得到应用。

                                                          分享:
                                                          0116512

                                                          摘要

                                                          Black phosphorus (BP) is a promising material for ultrafast and broadband photodetection because of its narrow bandgap from 0.35 eV (bulk) to 1.8 eV (monolayer) and high carrier mobility. Although photodetectors based on BP with different configurations have been reported, high photosensitivity was mostly observed in the visible range. A highly efficient BP-based infrared photodetector operated in the telecom spectral range, especially at 1550 nm, has not been demonstrated. Here, we report a Schottky-type photodetector based on thin BP flakes, operating in a broad spectral range from visible (635 nm) to infrared (1550 nm). A responsivity as high as 230 A·W?1 was achieved at 1550 nm with a source-drain bias of 1 V. The rise time is 4.8 ms, and the fall time is 6.8 ms. Under light illumination and external bias, the Schottky barrier between the BP and metal was reduced, leading to efficient photocurrent extraction. The unprecedented performance of the BP photodetector indicates intriguing potential for sensing, imaging, and optical communication.

                                                            PDF全文Chinese Optics Letters | 2018,16(02):020002
                                                            分享:
                                                            079151

                                                            摘要

                                                            The all-optical approach plays an important role in ultrafast all-optical signal processing, and the all-fiber scheme has a wide application in optical communications. In this letter, we investigate an all-optical modulator using few-layer molybdenum disulfide (MoS2)-polyvinyl alcohol (PVA) thin films based on the thermo-optic effect and obtain a long-time stable modulated output by applying polarization interference. By absorbing the injected 980 nm pump (control light), MoS2 generates heat, changes the refractive index of MoS2, and modulates the polarization of light. The obtained thermal all-optical modulator has a rise time of 526 μs.

                                                              PDF全文Chinese Optics Letters | 2018,16(02):020003
                                                              分享:
                                                              053130

                                                              摘要

                                                              Initiated by graphene, two-dimensional (2D) layered materials have attracted much attention owing to their novel layer-number-dependent physical and chemical properties. To fully utilize those properties, a fast and accurate determination of their layer number is the priority. Compared with conventional structural characterization tools, including atomic force microscopy, scanning electron microscopy, and transmission electron microscopy, the optical characterization methods such as optical contrast, Raman spectroscopy, photoluminescence, multiphoton imaging, and hyperspectral imaging have the distinctive advantages of a high-throughput and nondestructive examination. Here, taking the most studied 2D materials like graphene, MoS2, and black phosphorus as examples, we summarize the principles and applications of those optical characterization methods. The comparison of those methods may help us to select proper ones in a cost-effective way.

                                                                PDF全文Chinese Optics Letters | 2018,16(02):020006
                                                                分享:
                                                                043110

                                                                摘要

                                                                A highly stable Q-switched laser incorporating a mechanically exfoliated tungsten sulphoselenide (WSSe) thin sheet saturable absorber (SA) is proposed and demonstrated. The SA assembly, formed by sandwiching a thin WSSe sheet between two fiber ferrules within the erbium-doped fiber laser, is used to effectively modulate the laser cavity losses. The WSSe-based SA has a saturation intensity of ~0.006 MW/cm2 and a modulation depth of 7.8%, giving an optimum Q-switched laser output with a maximum repetition rate of 61.81 kHz and a minimum pulse width of 2.6 μs. The laser’s highest output power of 0.45 mW and highest pulse energy of 7.31 nJ are achieved at the maximum pump power of 280.5 mW. The tunability of the cavity’s output at the maximum pump power is analyzed with a C-band tunable bandpass filter, giving a broad tunable range of ~40 nm, from 1530 nm to 1570 nm. The output performance of the tunable Q-switched laser correlates well with the gain spectrum of erbium-doped fibers, with the shift in the gain profile as a result of the saturated SA.

                                                                  PDF全文Chinese Optics Letters | 2018,16(02):020009
                                                                  分享:
                                                                  042103

                                                                  摘要

                                                                  Faraday effect measurements of holmium oxide (Ho2O3) ceramics-based magneto-optical materials, highly potential material candidates for high-energy laser Faraday isolators, are presented in this paper. Temperature dependence of the Verdet constant of nondoped Ho2O3 ceramics was measured for temperatures 15–305 K at $1.064~\unicode[STIX]{x03BC}\text{m}$ wavelength. The Verdet constant dispersion for wavelengths 0.5–$1~\unicode[STIX]{x03BC}\text{m}$ and $1.064~\unicode[STIX]{x03BC}\text{m}$ was measured for both nondoped Ho2O3 ceramics and Ho2O3 ceramics doped with terbium Tb3+ (0.2 at. %) and cerium Ce3+ (0.1 at. %) ions. The results suggest that the relatively low level of doping of Ho2O3 with these ions has no significant boosting impact on the Faraday effect. Therefore, other compositions of Ho2O3 ceramics-based magneto-optical materials, as well as various doping concentrations, should be further examined.

                                                                    分享:
                                                                    041114

                                                                    摘要

                                                                    High-power ultrafast fiber lasers operating at the 2 μm wavelength are extremely desirable for material processing, laser surgery, and nonlinear optics. Here we fabricated large-core (LC) double-cladding Tm-doped silica fiber via the sol-gel method. The sol-gel-fabricated Tm-doped silica (SGTS) fiber had a large core diameter of 30 μm with a high refractive index homogeneity (Δn=2×10?4). With the newly developed LC SGTS fiber as the gain fiber, high-power mode-locking was realized. By using a semiconductor saturable absorber mirror (SESAM) as a mode locker, the LC SGTS fiber oscillator generated mode-locked pulses with an average output power as high as 1.0 W and a pulse duration of 23.9 ps at the wavelength of 1955.0 nm. Our research results show that the self-developed LC Tm-doped silica fiber via the sol-gel method is a promising gain fiber for generating high-power ultrafast lasers in the 2 μm spectral region.

                                                                      PDF全文Chinese Optics Letters | 2018,16(02):020020
                                                                      分享:
                                                                      03993

                                                                      摘要

                                                                      The potential of bulk-like WTe2 particles for the realization of a passive Q-switch operating at the 1 μm wavelength was investigated. The WTe2 particles were prepared using a simple mechanical exfoliation method together with Scotch tape. By attaching bulk-like WTe2 particles, which remained on the top of the sticky surface of a small segment of the Scotch tape, to the flat side of a side-polished fiber, a saturable absorber (SA) was readily implemented. A strong saturable absorption was then readily obtained through an evanescent field interaction with the WTe2 particles. The modulation depth of the prepared SA was measured as ~2.18% at 1.03 μm. By incorporating the proposed SA into an all-fiberized ytterbium-doped fiber ring cavity, stable Q-switched pulses were readily achieved.

                                                                        PDF全文Chinese Optics Letters | 2018,16(02):020017
                                                                        分享:
                                                                        03895

                                                                        摘要

                                                                        Materials in the transition metal dichalcogenide family, including WS2, MoS2, WSe2, and MoSe2, etc., have captured a substantial amount of attention due to their remarkable nonlinearities and optoelectronic properties. Compared with WS2 and MoS2, the monolayered MoTe2 owns a smaller direct bandgap of 1.1 eV. It is beneficial for the applications in broadband absorption. In this letter, using the magnetron sputtering technique, MoTe2 is deposited on the surface of the tapered fiber to be assembled into the saturable absorber. We first implement the MoTe2-based Q-switched fiber laser operating at the wavelength of 1559 nm. The minimum pulse duration and signal-to-noise ratio are 677 ns and 63 dB, respectively. Moreover, the output power of 25 mW is impressive compared with previous work. We believe that MoTe2 is a promising 2D material for ultrafast photonic devices in the high-power Q-switched fiber lasers.

                                                                          PDF全文Chinese Optics Letters | 2018,16(02):020007
                                                                          分享:
                                                                          037109

                                                                          摘要

                                                                          A diode-pumped Tm:YLF passively Q-switched laser at 2 μm was first demonstrated by using graphene oxide (GO) as a saturable absorber (SA). In this letter, continuous-wave (CW) laser and pulse laser performances were studied meticulously and systematically. It reasonably showed the dependence of the pulse duration, pulse energy, and pulse repetition rate on the absorbed power. A maximum repetition rate of 38.33 kHz and a single pulse energy of 9.89 μJ were obtained.

                                                                            PDF全文Chinese Optics Letters | 2018,16(02):020013
                                                                            分享:
                                                                            031108

                                                                            摘要

                                                                            We have prepared the graphene/MoS2 heterostructure by a hydrothermal method, and presented its nonlinear absorption parameters and application as a nonlinear optical modulator in the mid-infrared region. Using the nonlinear optical modulator, stable passively Q-switched operation of an Er3+-doped ZrF4-BaF2-LaF3-AlF3-NaF (ZBLAN) fiber laser at ~2.8 ?μm can be obtained. The Q-switched Er3+-doped ZBLAN fiber laser can yield per-pulse energy up to 2.2 μJ with the corresponding pulse width and pulse repetition rate of 1.9 μs and 45 kHz, respectively. Our results indicate that the graphene/MoS2 heterostructure can be a robust optical modulator for pulsed lasers in the mid-infrared spectral range.

                                                                              PDF全文Chinese Optics Letters | 2018,16(02):020012
                                                                              分享:
                                                                              03099

                                                                              查看更多

                                                                              摘要

                                                                              通过单个自由曲面反射器的反射, 令光源发出的能量重新分布, 在特定照明面上实现所需照明, 从而简化了投影设备中的照明系统, 使设备的进一步小型化成为可能。根据给出的光源辐射特性和所需实现的照明面上的能量分布, 可得到一组偏微分方程, 数值差分求解直接得到自由曲面反射器。光源采用发光面积1 mm×1 mm朗伯体发光的LED, 视角为120°, 照明面为4∶3的均匀矩形光斑。设计了两种自由曲面反射器, 并用软件对得到的曲面进行了照明模拟, 模拟得到的照明均匀性接近90%。两种反射器在光轴方向上的投影尺寸均小于25 mm, 垂直光轴方向上投影长度均小于22 mm, 照明系统总长均小于40 mm, 结构紧凑, 适用于小型LED投影设备。

                                                                              PDF全文光学学报 | 2007,27(03):540-544
                                                                              分享:
                                                                              035517731

                                                                              摘要

                                                                              飞秒激光微加工技术具有加工精度高、热效应小、损伤阈值低以及能够实现真正的三维微结构加工等优点,这些特性是传统的激光加工技术所无法取代的。首先回顾了激光微加工和超短脉冲激光技术的发展历史,然后介绍超短脉冲激光与金属和介质材料相互作用的机制,接着阐述了飞秒激光直写、干涉和投影制备等各种加工方法的原理,重点讨论飞秒激光在三维光子器件集成、微流体芯片制备及其在生化传感方面的应用等,最后展望了飞秒激光微加工领域所面临的机遇和挑战,指出了未来的研究方向。

                                                                              PDF全文中国激光 | 2007,34(05):595-622
                                                                              分享:
                                                                              0152019112

                                                                              摘要

                                                                              高分辨力空间相机的光学系统决定相机的外形尺寸和布局,为了相机的小型化、轻量化和结构稳定,针对某一种光学设计指标要求,分析比较多种光学系统结构是有必要的。本文针对在太阳同步轨道上用TDI CCD 推扫方式成像的高分辨力可见光相机,在设轨道高度为500 km,地面像元分辨力达到 0.5 m的情况下,用CODE V软件分析研究了6种可能的相机光学系统结构,得到了不同相对孔径和不同视场角的光学设计结果,并给出了可供参考的6种光学系统设计数据。指出在实际工程应用时,应根据不同的地面覆盖宽度的需求确定光学系统视场角,然后根据不同的视场角选定能满足这个视场角要求且尺寸最小的光学系统结构形式。

                                                                              PDF全文光学 精密工程 | 2008,16(11):2164-2172
                                                                              分享:
                                                                              0966011

                                                                              摘要

                                                                              光子晶体光纤(PCF),又称为多孔光纤(HF)或微结构光纤(MF),是一种单一介质,并由波长量级的空气孔构成微结构包层的新型光纤。光子晶体光纤呈现出许多在传统光纤中难以实现的特性,从1996年世界上制造出第一根光子晶体光纤以来,它便受到了广泛关注并成为近年来光学与光电子学研究的一个热点。介绍了光子晶体光纤的制作工艺、工作原理、基本特性、目前的研究重点和进展情况,重点评述了光子晶体光纤非线性光学方面的研究及其潜在的应用。

                                                                              PDF全文中国激光 | 2006,33(01):57-66
                                                                              分享:
                                                                              1238230776

                                                                              摘要

                                                                              综述了近年来棒状、盘片、光纤和热容等高平均功率全固态激光器的进展和国内近期的工作。围绕限制激光器输出平均功率提高和激光光束质量下降的热效应问题, 比较了各类激光器的优缺点。总结了减小或补偿无用热不利影响的现有技术手段, 指出减小激光器热效应可能的技术途径。

                                                                              PDF全文中国激光 | 2009,36(07):1605-1618
                                                                              分享:
                                                                              0134622569

                                                                              摘要

                                                                              以GaN基功率型发光二极管(LED)为代表的半导体照明光源, 具有其他传统光源无法比拟的诸多优点, 被公认为21世纪最有价值的新型光源。充分发挥功率型LED的优势, 利用非成像光学进行面向实际应用的功率型LED封装光学系统设计, 以高端半导体照明光源的制造为突破点, 带动整个半导体照明产业的快速进步, 已成为半导体照明技术发展的战略选择。回顾了非成像光学的历史、研究进展以及在半导体照明中的应用, 并通过设计实例, 介绍了面向功率型LED光线耦合、二维给定光分布以及三维给定光分布问题的非成像光学系统设计原理与解决方案。

                                                                              PDF全文中国激光 | 2008,35(07):963-971
                                                                              分享:
                                                                              036418146

                                                                              摘要

                                                                              将相位检测面形术(PMP)用于大尺度、 高精度三维面形测量中。 采用文中提出的双向高度坐标校正法, 可以得到精确的物面三维坐标。 提出了一种新的基于洪水算法的图像拼接法, 采用此方法可以按最佳的途径将各子区域的高度分布合成整个物面的高度分布。

                                                                              PDF全文光学学报 | 2000,20(06):792-796
                                                                              分享:
                                                                              0023020

                                                                              摘要

                                                                              采用两个中心波长约976 nm准直输出的高功率半导体激光模块为抽运源,通过空间滤波和非球面透镜耦合技术,双端抽运长度为21 m的大模场面积国产掺镱双包层光纤,获得了714.5 W的高功率连续激光输出。采用反向抽运,当入纤抽运功率为760 W时,激光输出功率达到501 W;采用双端抽运,当入纤抽运功率为1137 W时,获得了714.5 W的高功率连续输出,光光转换效率为62.8%,斜率效率为67%。

                                                                              PDF全文光学学报 | 2006,26(07):1119-1120
                                                                              分享:
                                                                              024227205

                                                                              摘要

                                                                              综述了用于下一代移动通信的光纤毫米波副载波通信技术(ROF)的研究进展。介绍了系统的基本构想和涉及的关键技术。着重介绍几种毫米波副载波光发射器以及有关光学技术的新进展,包括外调制器方法、射频上转换法、光学外差法、毫米波调制光脉冲发生器等;简要介绍了ROF接收技术、系统技术和有关应用的研究动向。

                                                                              PDF全文中国激光 | 2006,33(04):481-488
                                                                              分享:
                                                                              022221597

                                                                              摘要

                                                                              综述了现有的3类激光光束质量评价方法, 即近场质量、远场质量和传输质量。主要的评价参数包括近场调制度和对比度、聚焦光斑尺寸、远场发散角、衍射极限倍数β因子、斯特列尔比、环围能量比以及M2因子等。讨论了它们各自的适用范围、优点和局限性。提出了采用M2因子矩阵以表述光束的像散特性, 给出了M2因子的不变量。

                                                                              PDF全文中国激光 | 2009,36(07):1643-1653
                                                                              分享:
                                                                              03719318

                                                                              摘要

                                                                              提出一种在数字加权滤波和调制度分析基础上形成可靠性控制模板,并按可靠度排序进行位相展开的新方法。该法用于傅里叶变换轮廓术中,可以兼顾所求位相精度和位相展开的可靠度,适合复杂物体面形的测量。给出了傅里叶变换轮廓术对复杂物体面形测量的应用实例。

                                                                              PDF全文光学学报 | 1998,18(09):1228-1233
                                                                              分享:
                                                                              085126543

                                                                              摘要

                                                                              讨论了由无窗硅光电二极管构成的反射式陷阱探测器的设计方案和工作原理,通过实验测试证明它具有良好的线性、空间响应均匀性、偏振非敏感性和稳定性。在可见波段的7个激光波长上(488nm~786nm),通过低温辐射计标定了陷阱探测器的绝对光谱响应率,不确定度小于0.035%,比现有的标准辐射源的精度提高了约2个量级,证明其可以作为高精度的绝对光谱响应率标准探测器。

                                                                              PDF全文光学学报 | 2001,21(06):749-752
                                                                              分享:
                                                                              07017827

                                                                              摘要

                                                                              研究了光在一维周期性介电材料中的传播特性, 指出传统的高反膜只是光子晶体的一个特例, 从而从光子晶体的角度对多层膜系的设计提出了一条新的思路, 同时研究了材料的介电常数以及结构与高反带带宽之间的关系。 最后通过在多层膜中引入掺杂(中间一层被另一种介质所代替), 得到第一能隙中掺杂模式的频率与掺杂材料的介电常数之间的对应关系, 由此提出一种精确测量介质介电常数的方法。

                                                                              PDF全文光学学报 | 2000,20(06):728-734
                                                                              分享:
                                                                              0025138

                                                                              摘要

                                                                              光电跟踪和测量设备用于测量飞行器在空中的飞行轨迹,作为飞行器飞行性能的评价.随着现代技术的发展,对飞行器性能提出愈来愈高的要求,从而也对跟踪和测量飞行器飞行轨迹的光电跟踪和测量设备提出了相应的技术进步要求,特别是对其测量精度指标.如何做好和完善误差分析、误差分配和误差综合,成为研制更高性能的光电跟踪测量设备总体设计中的一个重要问题,贯穿从可行性论证、方案论证、方案设计、设计、制造、装调、直到试验等整个研制过程.就这一类设备中最为复杂的机载光电跟踪测量设备的目标定位误差(即3轴上的测量误差),通过建立从被测目标到地面中心测量站9个坐标系,进行31次线性变换,构造35个变量的统一测量方程;进行测量误差因素的分析和分配,以及用蒙特卡洛法来分析和计算系统的目标定位误差.

                                                                              PDF全文光学 精密工程 | 2005,13(02):105-116
                                                                              分享:
                                                                              007316

                                                                              摘要

                                                                              可调谐二极管激光吸收光谱(TDLAS)技术利用二极管激光器波长调谐特性,获得被测气体的特征吸收光谱范围内的吸收光谱,从而对污染气体进行定性或者定量分析,这种方法不仅精度较高,选择性强而且响应速度快,已经被用于大气痕量气体监测以及工业控制。在对空气中的痕量气体进行检测中,由于气体浓度较低,需要和长吸收光程技术相结合。将可调谐二极管激光吸收光谱与经过108次反射后达到27 m光程的多次反射池相结合研制了用于地面环境空气中甲烷含量监测的便携式吸收光谱仪,并结合了用于微弱信号检测的二次谐波检测技术,从而达到了体积分数低于1×10-7的检测限,并利用不同体积分数的甲烷气体对系统进行了测试,得到了很好的测试结果。

                                                                              PDF全文光学学报 | 2006,26(01):67-70
                                                                              分享:
                                                                              012017785

                                                                              摘要

                                                                              激光光斑中心检测是光学测量中常用的关键技术.检测算法的精度和速度直接影响了测量的精度及速度,传统的检测算法如重心法、Hough变换法等在检测精度或速度上存在不足.基于圆拟合的激光光斑中心检测算法是根据最小二乘原理用圆来逼近激光光斑轮廓,该算法除了可以检测光斑中心外,还可以检测光斑半径,达到亚像素级的定位精度,具有很快的计算速度,可适用于实时的光学测量.

                                                                              PDF全文红外与激光工程 | 2002,31(03):275-279
                                                                              分享:
                                                                              01189767

                                                                              摘要

                                                                              调制传递函数(MTF)是描述光学成像系统信息传递频率特性的一个关键指标。在成像系统满足线性和空间不变性的条件下,对于含有点、狭缝和边缘等不同特征的图像,可以使用相应的方法计算得到成像系统的MTF。采用了倾斜刃边法来计算得到成像系统的MTF,分析了成像器件和算法步骤对计算结果产生的影响,进行了相应的校正,提高了计算结果的准确性。运用MTF补偿(MTFC)技术,分别使用了镜头MTF的设计值、测量值和计算值对实际拍摄得到的图像进行了复原。通过对以上3种复原图进行对比,实验结果证明了MTF计算值的可靠性和用于降质图像复原时的有效性。

                                                                              PDF全文光学学报 | 2010,30(10):2891-2897
                                                                              分享:
                                                                              01626096

                                                                              摘要

                                                                              随机并行梯度下降算法能不依赖波前传感器直接对系统性能进行优化。以32单元变形镜为校正器,采用随机并行梯度下降算法建立了自适应光学系统仿真模型。通过分析该系统对静态波前畸变的校正能力,验证了随机并行梯度下降算法的收敛性;讨论了算法增益系数、随机扰动幅度与收敛速度的关系,并指出通过算法增益系数的自适应调整可以改进算法的收敛速度。

                                                                              PDF全文光学学报 | 2007,27(08):1355-1360
                                                                              分享:
                                                                              0787023

                                                                              摘要

                                                                              对几台国内外典型的星载高光谱成像仪所采用的光学系统结构进行了分析,阐述了棱镜色散、光栅色散、傅里叶变换3种主流高光谱成像仪分光方式的结构原理和优缺点。根据宽波段、小型化的研究目标,设计了一个全反射式高光谱成像仪光学系统。该系统由离轴非球面三反射镜望远成像系统和两个Offner凸光栅光谱成像系统组成,通过改变两个光谱成像系统的变倍比来实现两种探测器的匹配。给出的该系统的详细设计结果显示,光学系统128个谱段的调制传递函数均达到0.6以上,畸变<0.44%,谱线弯曲<0.03%。实验结果表明,选定的全反射式光学系统满足小型化星载高光谱成像仪的技术要求,有效降低了仪器的体积和质量,通过加大光学系统的相对孔径弥补了光栅衍射效率低的缺点。

                                                                              PDF全文光学 精密工程 | 2009,17(11):2629-2637
                                                                              分享:
                                                                              0514522

                                                                              摘要

                                                                              卫星激光通信具有巨大的潜在应用价值, 国际上已实现高码率、小型化、轻量化和低功耗激光通信终端, 全文的第一部分即“链路和终端技术”综述了卫星激光通信的国外进展, 介绍了终端的关键技术, 讨论了终端设计思想。第二部分(另文)将讨论和介绍卫星激光通信终端地面检测和验证技术。

                                                                              PDF全文中国激光 | 2007,34(01):3-20
                                                                              分享:
                                                                              0117527537

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                                                                              摘要

                                                                              An analytical model for hole boring proton acceleration by a circularly-polarized CO2 laser pulse in a gas jet is developed. The plasma density profile near the density peak is taken to be rectangular, with inner region thickness l around a laser wavelength and density 10% above the critical, while the outside density is 10% below the critical. On the rear side, plasma density falls off rapidly to a small value. The laser suffers strong reflection from the central region and, at normalized amplitude a0≥1, creates a double layer. The space charge field of the double layer, moving with velocity vfz^, reflects up-stream protons to 2vf velocity, incurring momentum loss at a rate comparable to radiation pressure. Reflection occurs for vf≤ωp (zflm/mp)-1/2 , where m and mp are the electron and proton masses, zf is the distance traveled by the compressed electron layer and ωp is the plasma frequency. For Gaussian temporal profile of the laser and parabolic density profile of the upstream plasma, the proton energy distribution is narrowly peaked.

                                                                              分享:
                                                                              001044

                                                                              摘要

                                                                              We have developed a conceptual design of a 15-TW pulsed-power accelerator based on the linear-transformer-driver (LTD) architecture described by Stygar [W. A. Stygar et al., Phys. Rev. ST Accel. Beams 18, 110401 (2015)]. The driver will allow multiple, high-energy-density experiments per day in a university environment and, at the same time, will enable both fundamental and integrated experiments that are scalable to larger facilities. In this design, many individual energy storage units (bricks), each composed of two capacitors and one switch, directly drive the target load without additional pulse compression. Ten LTD modules in parallel drive the load. Each module consists of 16 LTD cavities connected in series, where each cavity is powered by 22 bricks connected in parallel. This design stores up to 2.75 MJ and delivers up to 15 TW in 100 ns to the constant-impedance, water-insulated radial transmission lines. The transmission lines in turn deliver a peak current as high as 12.5 MA to the physics load. To maximize its experimental value and flexibility, the accelerator is coupled to a modern, multibeam laser facility (four beams with up to 5 kJ in 10 ns and one beam with up to 2.6 kJ in 100 ps or less) that can provide auxiliary heating of the physics load. The lasers also enable advanced diagnostic techniques such as X-ray Thomson scattering and multiframe and three-dimensional radiography. The coupled accelerator-laser facility will be the first of its kind and be capable of conducting unprecedented high-energy-densityephysics experiments.

                                                                              分享:
                                                                              01920

                                                                              摘要

                                                                              Proton generation, transport and interaction with hollow cone targets are investigated by means of two-dimensional PIC simulations. A scaled-down hollow cone with gold walls, a carbon tip and a curved hydrogen foil inside the cone has been considered. Proton acceleration is driven by a 1020 W?cm2 and 1 ps laser pulse focused on the hydrogen foil. Simulations show an important surface current at the cone walls which generates a magnetic field. This magnetic field is dragged by the quasi-neutral plasma formed by fast protons and co-moving electrons when they propagate towards the cone tip. As a result, a tens of kT Bz field is set up at the cone tip, which is strong enough to deflect the protons and increase the beam divergence substantially. We propose using heavy materials at the cone tip and increasing the laser intensity in order to mitigate magnetic field generation and proton beam divergence.

                                                                              分享:
                                                                              00612

                                                                              摘要

                                                                              为了降低光学小卫星相机次镜上的随机响应, 提出了一种蜂窝夹层板结构的优化设计方法, 对小卫星光学载荷的蜂窝安装板进行结构参数的优化设计。首先, 以整星一阶频率不低于40 Hz为优化目标, 对蜂窝芯子密度进行优化, 根据三明治夹心理论, 推导计算了蜂窝芯子等效力学参数。然后, 以次镜的随机响应为优化目标, 对蜂窝夹层板的碳纤维面板进行铺层优化设计, 得到最优铺层顺序为[0/45/90/-45]S, 总厚度为0.8 mm。根据以上计算得出蜂窝芯子及碳纤面板等效参数, 对整星进行分析。最后, 开展了整星振动试验, 测量了整星模态和响应, 对试验数据进行采集。结果表明: 整星模态为42.2 Hz, 次镜最大随机响应为11.1g, 均在合理范围之内, 满足了组件力学要求。

                                                                              PDF全文红外与激光工程 | 2017,46(12):1218004
                                                                              分享:
                                                                              06583

                                                                              摘要

                                                                              针对X射线线阵探测器像素响应不均而造成X射线图像产生竖条纹, 以及由探测器本身和外界产生噪声干扰的问题, 提出了一种新型的校正与滤波模型, 解决了传统校正方法因忽略噪声影响而使得校正完成后数据波动较大的问题。结合X射线特性及X射线线阵探测器的成像原理, 分析了像素响应不均时的输出特性及噪声, 建立了改进的两点校正算法与基于偏微分方程的半隐式差分滤波模型。实验证明, 分辨率为1×9 216的X射线线阵探测器在经过该模型校正后, 有效地解决了像素响应不均的问题, 抑制了噪声的影响, 在位深为16 bit的情况下, 平均均方误差低于五个灰度级, 提高了X射线图像检测的质量。

                                                                              PDF全文红外与激光工程 | 2017,46(12):1226001
                                                                              分享:
                                                                              00560

                                                                              摘要

                                                                              根据菲涅耳衍射积分理论, 提出了X射线光栅相衬成像系统的仿真模型。以聚甲基丙烯酸甲酯(PMMA)小球作为成像物体模型, 选取30 keV的X射线做模拟计算。通过仿真, 得到了穿过球体和相位光栅的X射线波前的变化。采用多步位移法从模拟条纹图中恢复出了PMMA小球的相位信息, 并分析了莫尔条纹对比度对成像质量的影响, 为实际的实验提供可靠的参数选择。经过仿真得到的相移信息与通过实验得到一致, 验证了仿真算法的正确性。

                                                                              PDF全文红外与激光工程 | 2017,46(12):1220002
                                                                              分享:
                                                                              00557

                                                                              摘要

                                                                              高光谱遥感图像具有特征(波段)数多、冗余度高等特点, 因此特征选择成为高光谱分类的研究热点。针对此问题, 提出了空间结构与光谱结构同时保持的高光谱数据分类算法。考虑高光谱图像的物理特性, 首先对图像进行加权空谱重构, 使图像的空间结构信息自动融入光谱特征, 形成空谱特征集; 对利用最小二乘回归模型保存数据集的全局相似性结构的基础上, 加入局部流形结构正则项, 使挑选的特征子集更好地保存数据集的内在本质结构; 讨论了窗口大小和正则参数对分类精度的影响。对Indian Pines、PaviaU和Salinas数据集的实验表明, 该算法得到的特征子集的总体分类精度达到93.22%、96.01%和95.90%。该算法不仅充分利用了高光谱图像的空间结构信息, 而且深入挖掘了数据集的内在本质结构, 从而得到更有鉴别性的特征子集, 相比传统方法明显提高了分类精度。

                                                                              PDF全文红外与激光工程 | 2017,46(12):1228001
                                                                              分享:
                                                                              00555

                                                                              摘要

                                                                              通过对InGaAsP/InP 单光子雪崩二极管(SPAD)的探测效率、暗计数率等基本特性与该器件的禁带宽度、电场分布、雪崩长度、工作温度等参数之间关系的分析, 采用比通常的InxGaAs(x=0.53)材料具有更宽带隙的InxGa1-xAsyP1-y(x=0.78, y=0.47)材料作为光吸收层, 并且精确控制InP倍增层的雪崩长度, 有效地降低了SPAD的暗计数率。其中InGaAsP材料与InP材料晶格匹配良好, 可在InP衬底上外延生长高质量的InGaAsP/InP异质结, InGaAsP材料的带隙为Eg=1.03 eV, 截止波长为1.2 μm, 可满足1.06 μm单光子探测需要。同时, 通过设计并研制出1.06 μm InGaAsP/InP SPAD, 对其特性参数进行测试, 结果表明, 当工作温度为270 K时, 探测效率20%下的暗计数率约20 kHz。因此基于时间相关单光子计数技术的该器件可在主动淬灭模式下用于随机到达的光子探测。

                                                                              PDF全文红外与激光工程 | 2017,46(12):1220001
                                                                              分享:
                                                                              00544

                                                                              摘要

                                                                              为了实现对玻璃面板油墨层厚度的检测, 提出了一种满足工业化检测需要的玻璃面板油墨厚度无损在线检测系统。首先, 基于结构光测量原理进行非接触式测量, 进一步提出了基于自适应提取算法的油墨厚度数字化定量计算模型, 对采集到的携带油墨厚度信息的亮线图像进行处理, 该模型非常适用于非接触式数字化检测; 其次, 建立了完整的检测系统, 将标准油墨面板作为油墨检测的评价标准, 多次测量拟合定标系数;最后, 该玻璃面板油墨厚度无损测量系统的最大检测厚度达23 mm, 检测精度优于4 μm, 通过对玻璃面板油墨层厚度的检测, 实现了对油墨厚度的高精度、快速、无损检测, 具有广阔的应用前景。

                                                                              PDF全文红外与激光工程 | 2017,46(12):1217009
                                                                              分享:
                                                                              00523

                                                                              摘要

                                                                              为了满足空间探测对衍射望远镜的发展需求, 针对某衍射光学系统设计了一种空间可展开衍射望远镜。首先, 根据Serrurier桁架原理及优化设计理论确定了文中所用展开结构的形式及几何尺寸, 并针对某衍射光学系统设计了一种新型自展开结构; 其次, 建立了该展开结构的有限元模型并分析了其展开后的特性; 最后, 搭建了原理样机并对其进行了实验研究。实验结果表明: 该展开结构的展开距离为2.9 m, 展开后的重复精度误差小于2 mm, 偏心小于0.3 mm, 倾角小于0.2°, 且可通过促动器将其展开精度调整至微米级, 能够满足空间衍射望远镜自展开机构的结构简单、质量轻、稳定可靠、精度高等要求。

                                                                              PDF全文红外与激光工程 | 2017,46(12):1218001
                                                                              分享:
                                                                              00520

                                                                              摘要

                                                                              为了发挥单管半导体激光器的优势, 获得光纤耦合模块多波长、高功率、高亮度的光束输出, 利用ZEMAX软件仿真模拟, 设计了一种单管光纤耦合模块。此模块将32支输出波长分别为915 nm、975 nm, 输出功率为15 W的单管半导体激光器, 经过微透镜组快慢轴光束整形、空间合束、偏振合束、波长合束以及光束聚焦等一系列工艺后, 耦合进芯径200 μm、数值孔径0.22的光纤。模拟结果显示, 光纤输出功率467.46 W, 光纤前后耦合效率大于98.47%, 总耦合效率高于97.39%, 光功率密度高于12.86 MW/(cm2·sr), 达到了泵浦激光器和功率型器件的性能要求。使用Solidworks软件设计了相应的底板结构, 并结合ANSYS软件进行散热模拟分析, 结果显示该模块散热性能良好, 可行性较高。

                                                                              PDF全文红外与激光工程 | 2018,47(01):0105002
                                                                              分享:
                                                                              02516

                                                                              摘要

                                                                              Recent advances in experimental techniques and data processing allow in situ determination of mineral crystal structure and chemistry up to Mbar pressures in a laser-heated diamond anvil cell (DAC), providing the fundamental information of the mineralogical constitution of our Earth's interior. this work highlights several recent breakthroughs in the field of high-pressure mineral crystallography, including the stability of bridgmanite, the single-crystal structure studies of post-perovskite and H-phase as well as the identification of hydrous minerals and iron oxides in the deep lower mantle. the future development of high-pressure crystallography is also discussed.

                                                                              分享:
                                                                              00511

                                                                              摘要

                                                                              为解决传统“Brault”采样方法中参考信号过零点计算复杂、耗时较多的问题, 提出了基于傅里叶插值技术寻找过零点的方法。通过与其他插值方法进行比较研究, 结果表明, 这种方法确保了过零点信息准确性的同时简化了数据处理的复杂度, 得到的过零点信息线性拟合系数大于0.999。在2 100~2 200 cm-1波段范围内, 当参考激光信号误差较小时, 傅里叶插值方法得到的仪器SNR是三次样条插值法所得到的1.03倍, 而线性插值方法与傅里叶插值方法得到的结果一致; 当参考激光信号误差较大时, 傅里叶插值方法得到的仪器SNR是线性插值方法得到的仪器SNR的1.05倍。

                                                                              PDF全文红外与激光工程 | 2018,47(01):0123001
                                                                              分享:
                                                                              04508

                                                                              摘要

                                                                              利用化学气相沉积法制备了三种类型多个超有序排列的多壁碳纳米管薄膜样品, 通过太赫兹时域光谱技术, 获取相位和振幅信息, 详细研究了薄膜在太赫兹波段的传输特性。结果表明: 超有序多壁碳纳米管薄膜在纳米管轴向方向与垂直于轴向方向表现出明显的光、电各向异性特性; 测试的介电常数实部为负, 虚部为正, 证实了制备的薄膜具有金属性; 薄膜具有的各向异性为研究其偏振特性提供了直接证据, 随着薄膜厚度的增加, 偏振度和消光比增加, 其9 ?滋m厚的自由薄膜度可以获得99%的偏振度。研究结果对开展超有序多壁碳纳米管薄膜在太赫兹偏振器、调制器与光开关等领域的研究有重要指导意义。

                                                                              PDF全文红外与激光工程 | 2017,46(12):1221001
                                                                              分享:
                                                                              00506

                                                                              摘要

                                                                              为了降低激光通信载荷在轨工作中空间环境对于光学系统的影响, 提高通信质量以及跟踪精度, 使用综合性能较好的高体分SiC/Al作为主镜材料, 并通过有限元分析确定了主镜结构的几个重要优化参数。提出了一种一体式主镜柔性支撑, 该结构避免了使用不同材料支撑组件线膨胀系数不匹配而产生的应力集中, 提高了主镜面形的温度稳定性, 并在此基础上降低了主镜及其支撑的总体质量, 实现了光学系统的轻量化。仿真分析表明, 该结构在重力释放条件下, 主镜面形误差PV值为λ/52, RMS值为λ/275。工作环境发生±4℃温度变化的情况下, 主镜面形误差PV值为λ/11, RMS值为λ/71。主镜及其一体化支撑基频为208 Hz, 主镜单独轻量化率为55.3%, 进行一体化设计后主镜及支撑相比传统设计轻量化率为19.87%, 能够满足总体指标要求。

                                                                              PDF全文红外与激光工程 | 2017,46(12):1218003
                                                                              分享:
                                                                              00505

                                                                              摘要

                                                                              针对锁模激光器微弱回波信号探测的需求, 提出了一种基于高速相关采样和在线实时并行累加处理算法相结合的方法, 对传统的模拟取样积分方法进行了改进, 可实现无参考信号条件下的实时数字累加检测。设计并实现了一套基于该方法的锁模激光器微弱回波信号检测原型系统, 使用12 bit@900 MSPS模拟-数字转换芯片(ADC)ADS5409对经光电转换之后的锁模激光回波信号进行波形采样, 并利用现场可编程逻辑门阵列(FPGA)芯片Kintex-7实现对ADC的控制及在线数据处理。系统测试结果表明,对于重复频率为8 MHz、平均功率为0.04 nW的锁模激光回波信号, 通过在FPGA内进行16 000次脉冲波形精确累加,可实现信号的有效检出, 且从波形采集完毕到输出检测结果的延时小于100 ns, 达到了高度的实时性。经900次重复实验, 检测效率达到100%, 且无“虚警”情况发生。

                                                                              PDF全文红外与激光工程 | 2017,46(12):1217002
                                                                              分享:
                                                                              03494

                                                                              摘要

                                                                              提出了一种基于复合光纤滤波器的在室温下稳定输出多波长掺铒光纤激光器, 该激光器由两个级联球状结构的马赫-增德尔干涉仪(MZI)和一个双折射光纤滤波器-Lyot滤波器组成。球状结构MZI是由光纤熔接机在一段单模光纤(SMF)放电设计而成的。Lyot双折射光纤滤波器是利用一段保偏光纤(PMF)和两个偏振控制器(PC)连接而成, 该结构可以诱导非线性偏振旋转效应和双折射光纤效应来抑制模式竞争产生多波长。Lyot滤波器和球状结构的MZI作为模式限制器件, 并且Lyot滤波器对级联球状结构MZI的透射谱进行调制, 其透射谱周期决定了复合滤波器结构的透射谱周期。在室温下, 该系统实现了边模抑制比约为40 dB的九个波长的同时激射, 且波长间隔约为0.68 nm, 与Lyot滤波器透射谱周期一致。为了验证输出波长的稳定性, 在2 h内, 每隔10 min观察输出的波长, 实验证明, 室温下中心波长输出功率的浮动小于0.67 dB。此外, 将两个球状结构MZI放置在高温炉上, 使其外界温度从30 ℃升至110 ℃时, 输出波长光谱的调谐范围可达到6.69 nm。

                                                                              PDF全文红外与激光工程 | 2018,47(01):0105001
                                                                              分享:
                                                                              00493

                                                                              摘要

                                                                              为满足某些国家工程的发展需要, 比如说航天领域内, 液态燃料液位监测作为飞行指标考核的一个关键参数, 检测精度直接影响到各类飞行器的指标实现效率。基于塑料光纤弯曲损耗和受抑全内反原理, 设计了一种可实现单点离散与多点连续的液位传感系统。理论分析后, 使用实际器材验证理论分析, 阐述了操作原则、系统结构和技术优势, 分析了进行液位测量的可行性。根据理论分析的结果, 基于已有器材搭建了离散和连续式液位传感系统, 同时设计了一套实验装置并利用该装置对传感系统进行了验证实验。实验结果表明: 所提出的新型液位传感系统不仅可以实现液位的测量, 而且具有较好的测量一致性和易实现性。其中连续液位测量系统达到了测试量程450 mm, 测试灵敏度为0.808 3 μW/mm的液位测量。对工程应用领域的具有较好的参考意义。

                                                                              PDF全文红外与激光工程 | 2017,46(12):1217001
                                                                              分享:
                                                                              00491

                                                                              摘要

                                                                              斜率和曲率混合型波前传感技术将子孔径内波前的一阶和二阶导数信息全部利用起来, 能够实现高阶像差的精密测量, 是区域型波前传感技术的一个重要发展方向。在利用子孔径波前振幅调制的斜率和曲率混合型波前传感器的基础上, 提出了一种基于质心探测的斜率和曲率信号提取算法, 实现各个子孔径内待测波前斜率、拉普拉斯曲率以及扭转曲率的直接测量。仿真结果表明, 在理想条件下, 单一子孔径内斜率和曲率信号的检测精度均在0.02λ(λ=632.8 nm)以内; 噪声水平小于10%时, 斜率和曲率信号的检测精度均在0.08λ以内。该算法具有较高的检测精度及良好的抗噪性。

                                                                              PDF全文红外与激光工程 | 2017,46(12):1217003
                                                                              分享:
                                                                              01489

                                                                              摘要

                                                                              为实现针对复杂深孔内轮廓表面几何参数的高精度测量, 建立了基于结构光的内轮廓检测系统, 但由于深孔内轮廓的曲面特性, 相机采集到的图像相比于内轮廓展开后的平面图像存在较大的几何畸变, 直接影响到内壁几何参数的量化精度。首先针对深孔内轮廓和内轮廓展开结构进行无差别建模, 分析两者之间的空间坐标转换关系; 然后综合考虑畸变矫正的精度和速度, 借鉴三次样条插值函数、离散映射等理念提出了基于离散映射的深孔内轮廓矫正算法, 实现针对深孔内轮廓的畸变在线矫正, 检测精度达到亚像素水平, 低于0.1 mm。

                                                                              PDF全文红外与激光工程 | 2017,46(12):1217008
                                                                              分享:
                                                                              00489

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                                                                              摘要

                                                                              在确定测距光谱通道数量和位置选定规则的基础上,为确定系统测距通道带宽的选定规则,本文以氧气A吸收带为例,从系统探测距离、目标与背景信噪比、系统工作海拔等约束条件对带宽的限制出发,利用MODTRAN和MATLAB软件综合仿真分析了满足系统实时性、目标信噪比及不同探测距离条件下通道带宽上下限的取值曲线。结果表明:相同条件下,系统平台海拔越高,带宽下限取值越小、范围越大、选取越灵活,系统探测距离越

                                                                              PDF全文 光学学报 | 2018,38(06):060103
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                                                                              摘要

                                                                              为克服复杂环境引起的干扰,增强运动目标检测的完整性和准确性,提出了一种多特征结合的运动目标检测方法。首先通过一种滞后多阈值建模的方法同时采用颜色和改进的局域二值模式(LBP)纹理特征对环境背景进行建模,并采用一种邻域补偿策略将基于两种特征提取得到的目标区域进行结合;之后采用结合Canny思想改进的Kirsch方法进行边缘提取,消除鬼影误识别像素,同时改善前景目标边缘。通过在公开评测数据集及实

                                                                              PDF全文 光学学报 | 2018,38(06):061204
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                                                                              摘要

                                                                              干涉条纹的相位非线性误差是制约扫描干涉场曝光系统最终曝光精度的关键环节之一。采用将高斯光束腰调整到基底的光学设计方案可以获得最小的干涉条纹非线性误差,但光学系统结构复杂。本文基于高斯光在远离束腰位置能得到直线度极高的干涉条纹设计方案,提出了一种新型的扫描干涉场曝光光学系统,建立了干涉条纹相位非线性误差关于高斯光束腰半径、入射角度以及束腰到基底距离的解析表达式,通过数值仿真的方法

                                                                              PDF全文 光学学报 | 2018,38(06):060501
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                                                                              摘要

                                                                              针对传统光纤弯曲损耗位移传感器中位移与损耗的非线性关系,高灵敏度和大量程不能兼得的问题,设计了一种U型缠绕式光纤弯曲损耗位移传感器,其包括U型回绕和螺旋绕轴,二者合称为U型缠绕。通过理论证明了被测位移量与光纤弯曲损耗之间的线性关系,推导了它们之间的表达式,讨论了螺旋绕轴方式对弯曲半径的影响和U型回绕方式对传感器精度的影响,进行了一系列的实验研究和性能测试。实验表明,传感器的测量范围

                                                                              PDF全文 光学学报 | 2018,38(06):060607
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                                                                              摘要

                                                                              为了探究高光谱技术在胃癌组织病理诊断当中的应用,将高光谱成像与显微系统结合,采集胃部切片组织的高光谱图像。针对胃癌细胞与正常细胞在410~910nm波段的光谱特性差异,提出了一种基于卷积神经网络模型(CNN)的胃癌组织分类方法,对原始光谱进行S-G平滑及一阶导数等预处理,通过分析光谱数据特点及模型分类效率,确定最佳网络结构及参数。实验结果表明:该模型对癌变和正常胃部组织的分类准确率为96.53%,

                                                                              PDF全文 光学学报 | 2018,38(06):061701
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                                                                              摘要

                                                                              海洋湍流是制约水下无线光通信、目标探测等激光系统应用的重要因素之一,由于复杂光束传输的闪烁及漂移特性理论推导较为复杂,海洋湍流激光传输特性的数值模拟更显重要。本文基于功率谱反演法产生海洋湍流相位屏,通过对多次传输过程的统计平均,仿真分析了不同海洋湍流参量下不同高斯阵列光束(矩形分布、径向分布及单束)长曝光光斑半径、漂移特性及光强闪烁特性。结果表明,光束长曝光光斑半径、光斑质心漂

                                                                              PDF全文 光学学报 | 2018,38(06):060104
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                                                                              摘要

                                                                              利用波长可调谐强飞秒激光脉冲,在中红外波段(800 ~2000 nm)系统地测量了氙原子单电离离子产量随光强变化曲线。基于两种不同理论模型(PPT模型[1]和ADK模型[2])进行计算并与实验结果对比分析,发现PPT在整个测量区域都与实验结果相符合,而ADK则在较长波长较高光强时(即深隧穿电离区域)也能较好重复出实验结果。两种理论模型在深隧穿电离区域的一致性及其在描述原子单电离方面的有效性在实验上得到了直接

                                                                              PDF全文 光学学报 | 2018,38(06):060201
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                                                                              摘要

                                                                              光的轨道角动量具有无限且相互正交的本征态,可以构成无穷维的希尔伯特空间,在大气激光通信系统应用光的轨道角动量进行调制,理论上能够获得无穷大的信道容量,从而大幅提高通信系统性能。这一系统对于轨道角动量态的稳定传输具有较高的要求,粒子散射是激光在大气中传输时必须面临的问题,而散射作用会引起轨道角动量态的展宽,最终导致通信系统性能下降。本文通过有限时域差分法,研究了单粒子散射对于拉盖

                                                                              PDF全文 光学学报 | 2018,38(06):062901
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                                                                              摘要

                                                                              通过光栅投影法可以获取物体的三维点云数据,但是对于形貌复杂的被测物体,由于测量方式本身含有的一定缺陷会导致所获取的点云数据出现孔洞区域,从而对后续处理造成影响。本文结合已有的SFM数据获取算法,提出了一种新的点云孔洞修补方法。该方法首先利用光栅投影法中所得到的二维相位信息来提取三维点云孔洞区域的边界点;接着将SFM获取的点云数据集和光栅投影法所采集的点云数据集进行配准,并提取出信息补

                                                                              PDF全文 光学学报 | 2018,38(06):061002
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                                                                              摘要

                                                                              介绍了一种利用倏逝波界面散射对单个纳米颗粒进行无标记成像的方法。分别使用全内反射倏逝波与表面等离激元两种倏逝波,与单个纳米颗粒相互作用,激发纳米颗粒极化并发生散射,所产生的界面散射与入射倏逝波发生干涉,形成了纳米颗粒极化场与抛物线形干涉条纹的特征成像。分别对直径为300纳米金颗粒、200纳米和100纳米聚苯乙烯颗粒进行了单个纳米颗粒无标记成像。比较了两种倏逝波界面散射对单个纳米颗粒成像

                                                                              PDF全文 光学学报 | 2018,38(06):062401
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                                                                              摘要

                                                                              非球形气溶胶穆勒散射矩阵的不确定性是影响偏振遥感精度的重要因素。在自主研制的MRTD气溶胶散射模型中,非球形气溶胶的穆勒散射矩阵计算需要以远场电场值为基础,因此近远场外推过程成为制约其模拟精度重要环节。为确定适用于MRTD散射模型的最佳近远场外推方案,在球形和非球形粒子情形下,系统对比分析了基于Huygens原理的表面积分方案以及基于电介质Helmholtz方程的体积积分方案对应的穆勒散射矩阵模拟精度

                                                                              PDF全文 光学学报 | 2018,38(06):062902
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                                                                              摘要

                                                                              论文实验研究了混沌激光通过脂肪乳液的时间点扩展函数的特性。实验采用混沌光作为光源,利用混沌信号的相关函数具有delta函数特性的特点,将探测到的信号与原始信号作互相关运算,提取出测量系统的时间点扩展函数。实验中通过增加脂肪乳液的浓度,使其散射系数增大而保持吸收系数不变,实验得到混沌光穿过不同浓度脂肪乳液的时间点扩展函数,从获得的时间点扩展函数中提取出差分路径长度因子,定性地分析脂肪乳液

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                                                                              摘要

                                                                              本文针对GEWEX-SRB、ISCCP-FD和CERES-SYN中上行长波辐射数据在极地地区的精度问题展开研究。实验利用极地地区的BSRN和CEOP两种地面观测数据作为参考数据,并采用降尺度方法对地面数据进行处理,最后对辐射产品进行精度评估。精度研究结果显示,在极地地区,3种常用上行长波辐射数据总体精度较低,均方根误差和平均绝对偏差基本在15W/m2以上,GEWEX-SRB,ISCCP-FD和CERES-SYN上行长波辐射产品的均方根误差均值

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                                                                              摘要

                                                                              本文采用直流磁控溅射的方式在浮法玻璃衬底上制备了立方多晶铁锰矿结构的ITO薄膜。为了实现ITO薄膜表面等离子体共振(SPR)波长的可控调节,通过改变薄膜沉积时间,制备出不同厚度的ITO薄膜。随着膜厚由16nm逐渐增加到271nm,其结晶程度得到增强,对应的载流子浓度由4.79*10^20cm^-3增大到2.41*10^21cm^-3,SPR波长由1802nm逐渐蓝移到1204nm,实现了近红外区域SPR波长较宽范围的可控调节。采用Drude自由电子气

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                                                                              摘要

                                                                              光纤激光器在光纤通信、光纤传感、光谱测量等众多领域有着广泛的应用。本文设计并研制了一种基于数字微镜器件(DMD)实现滤波功能并具有多个输出端口的宽带连续可调谐掺铒光纤激光器。用行波速率方程模型对激光器的输出特性进行了理论分析和仿真研究。在此基础上,实验搭建了具有8个输出端口的宽带可调谐掺铒光纤激光器实验系统,实验结果显示各端口输出波长范围50nm,完整覆盖了整个C波段并拓展到了S和L波段

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                                                                              摘要

                                                                              以具有复杂颗粒特征的商业食盐为模型样品,实验研究了激光诱导击穿光谱(LIBS)技术检测复杂颗粒状物质中微量元素光谱的稳定性。通过测量和分析食盐中Ca(800ppm)、Sr(35.1ppm)、Mg(6.4ppm)和Fe(1.7ppm) 四种目标微量元素在250-465nm波段的发射谱线强度、相对标准偏差和信噪比随距焦量、激光脉冲累加次数和光谱采集延迟时间的变化规律,确定了采集目标微量元素对应分析谱线的最优实验条件。基于优化的实验条件

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                                                                              摘要

                                                                              随着柔性显示面板技术的不断发展,曲面显示屏将被广泛应用。针对曲面显示屏设计背光照明系统使其在曲面屏上产生均匀的照度分布非常重要。本文通过优化LED阵列排布,使其在目标面上产生了均匀的照度分布。通过构建反映照度均匀性的目标函数,目标函数以阵列中各LED的位置坐标为变量,利用模拟退火算法对阵列中各LED的位置进行优化,使目标函数获得最小值。为了验证算法的可行性,分别以圆柱型曲面、抛物型曲面

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                                                                              摘要

                                                                              光场压缩态在量子超精密测量、量子通信和量子信息处理等领域有着重要的应用。目前实验上可以实现的两种类型的明亮光场压缩态分别为正交振幅分量(正交相位分量)压缩态和强度差压缩态。正交振幅分量噪声和强度差噪声分别对应于光场输出算符的一阶和二阶涨落。对于同一量子压缩光场采用以上两种不同的测量方案会得到不同的压缩度,本文对此加以理论解释。在输出信号没有损耗的情况下,强度差噪声和正交振幅分量

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                                                                              摘要

                                                                              采用疲劳裂纹扩展实验研究激光冲击处理技术对TC4钛合金激光熔覆修复件疲劳裂纹扩展速率的影响。利用光学显微镜和X射线衍射仪表征试样的微观结构,分别采用X-350A型残余应力测定仪,NANOVEA PS50型三维非接触式表面形貌仪和扫描电镜测量试样表层的残余应力,表面粗糙度和试样断口形貌。结果表明:激光修复区由β晶粒和沿晶界分布的α相组成,热影响区由等轴的α晶粒和β转变组织组成;激光冲击之后,衍射峰半高

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                                                                              摘要

                                                                              本文设计了一种中心椭圆空气孔缺陷的光子晶体光纤,采用全矢量有限元法,数值研究了该光纤基模的模场分布、双折射、色散、非线性及限制损耗特性。研究结果表明:模场能量束缚在光纤的纤芯。在λ=1.55μm处,光纤获得5.958×10-2的双折射,实现了10-2的高数量级。以及在1.50μm-1.60μm波段范围内,具有高负平坦色散,色散值在-549.2±5 ps/(nm.km)范围内。同时光纤的x偏振基模具有46.82W?1?km?1的高非线性系数,

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