Author Affiliations
Abstract
1 Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou 350002, China
2 University of Chinese Academy of Sciences, Beijing 100049, China
3 Fujian Science and Technology Innovation Laboratory for Optoelectronic Information of China, Fuzhou 350108, China
In this paper, the frequency difference of the eigen polarization modes of the Nd:YAG crystal laser at different polarization ratios is experimentally studied, and to the best of our knowledge, the correlation between the frequency difference of the eigenmodes and the output polarization degree is reported for the first time. Combined with the analysis of the polarization beam profile, it is proved that the polarized laser produced by the isotropic crystal is due to the frequency locking of the eigen polarization modes. The weak birefringence in the crystal causes the round-trip phase difference of the orthogonal polarization modes, which leads to the frequency difference between the polarization modes. By the adjustment of the cavity mirror, the anisotropic loss will interact with the round-trip phase difference. The eigen polarization modes can reach frequency degeneration, and then be coherently combined to produce linearly polarized laser output. This work provides a useful reference for understanding the physical mechanism of polarized lasers realized by isotropic crystals.
linear polarization frequency difference weak birefringence Chinese Optics Letters
2023, 21(11): 111401
1 中国科学院福建物质结构研究所，福州 350002
2 中国科学院大学，北京 100049
本文采用简易水热法，制备了稀土Nd离子掺杂的LiLuF4(LLF)微晶材料，对该微晶样品进行了物相分析、微观形貌分析和近红外波段光学性能的相关研究。LLF晶体属于四方晶系白钨矿结构，空间群为I41/a；采用水热法制备的LLF微晶料结晶性良好，颗粒尺寸在20 μm左右，优化后Nd∶LLF样品的氧含量为0.001 4%(质量分数)。在792 nm波长激发下，掺杂3%(摩尔分数)Nd离子的LLF微晶的最强荧光发射峰位于1 047 nm，属于近红外波段，其平均荧光寿命约为0.275 1 ms。进一步采用提拉法生长出Nd∶LLF晶体并评估了其激光性能。Nd∶LLF激光晶体在1 053 nm处的发射截面为8.13×10-20 cm2。激光性能测试发现，在1.2 W功率激发下，Nd∶LLF晶体可实现0.123 W的1 053 nm近红外激光输出。
稀土掺杂 水热法 激光 近红外波段 LiLuF4 LiLuF4 rare earth doping hydrothermal method laser near infrared band
1 陆军工程大学石家庄校区 电子与光学工程系, 石家庄 050003
2 陆军工程大学石家庄校区 导弹工程系, 石家庄 050003
为了准确地对陆基成像条件下高光谱图像的噪声水平进行评估, 提出了一种基于边缘剔除后残差调整的局部标准差法。首先将获取的高光谱图像分成若干个大小合适的子块, 而后利用Canny边缘检测算子检测出图像的边缘信息, 判断并剔除其中含有边缘的子块, 将剔除边缘子块后的均匀子块采用多元线性回归后求取残差的方法进行噪声估计。结果表明, 对同一幅陆基高光谱图像的不同子区域进行4×4像元与8×8像元分块, 得到的噪声总误差值分别为1.985×103与2.197×103。该噪声估计方法对陆基成像条件下高光谱图像的噪声评估具有较强的鲁棒性, 可为后续陆基高光谱图像处理与应用提供参考。
光谱学 高光谱图像 噪声评估 边缘剔除 spectroscopy hyperspectral image noise assessment edge elimination
1 中国科学院福建物质结构研究所光电材料化学与物理重点实验室, 福建 福州 350002
2 中国科学院大学, 北京 100049
3 福州大学化学学院, 福建 福州 350108
精确的简并范围是运用横模频率简并原理产生结构光场的重要条件。本文基于激光频谱研究了共焦腔处于1/2简并态时激光横模频率简并的现象,并提出一种更准确的简并范围测量方法。实验中详细观测输出激光频谱信号随腔长的变化。利用频谱信息,实现了对腔内不同阶横模在发生简并时动力学行为变化的监测。研究结果表明,当腔内不同阶横模发生频率简并时,不同简并族的横模未因模式竞争被抑制,而是共存于腔内。同时,利用激光频谱随腔长的变化,实现了对简并范围更准确的测量。简并过程中重点监测的两个频率信号随着腔进入简并态合并成一个频率信号,该状态在一段腔长范围内稳定存在。据此测得更精确的简并范围,对应腔长约为0.20 mm。此外,对实验中测得的频谱信号进行理论对比,频谱信号的实验值与理论值基本吻合。
激光器 横模 频谱 简并 简并范围 中国激光
2021, 48(20): 2001003
1 福州大学化学学院, 福建 福州 351100
2 中国科学院福建物质结构研究所, 福建 福州 351100
3 中国科学院上海硅酸盐研究所, 上海 200000
4 福建师范大学化学与材料学院, 福建 福州 351100
报道了基于a切Er,Yb∶YAl3(BO3)4晶体的被动调Q微片激光器的性能。使用波长为976 nm的光纤耦合半导体二极管作为端面抽运光源,使用初始透过率为96%的Co 2+∶MgAl2O4晶体作为可饱和吸收体,耦合输出镜在1500~1600 nm波段范围的透过率为2.5 %,整个微片激光器的腔长为2.7 mm。在注入功率为7.2 W 时,激光器成功得到了发射波长为1530 nm、重复频率为127 kHz的稳定线性偏振的脉冲输出,对应的脉冲能量和脉冲宽度分别为1.8 μJ和12 ns。
大气光学 a切Er Yb∶YAl3(BO3)4晶体; Co
2+∶ MgAl2O4晶体; 被动调Q 微片激光器 线性偏振 中国激光
2021, 48(13): 1301004
1 陆军工程大学石家庄校区电子与光学工程系, 河北石家庄 050003
2 解放军 94019部队, 新疆和田 848000
在市场需求驱动下, 非制冷红外测辐射热计阵列在多个领域正逐步应用, 对其激光干扰的研究也被提上了日程。本文以多晶硅探测器为例, 结合非制冷微测辐射热计阵列的构造和工作原理, 分析了激光辐照作用下的温度响应；通过 10.6 .m连续激光的辐照实验, 得到了像元阵列进入不同损伤状态对应的激光功率范围, 分析了激光损伤的热效应机制, 指出干扰面积大于光斑面积是由于热量的“倒灌”；将战场上激光传输的影响简单等效为斩波调制, 研究了调制频率和占空比对激光干扰效果的影响。经分析得出, 在调制频率 100～500 Hz、占空比 0.1～0.5的范围内, 连续激光对非制冷微测辐射热计在传输等效调制频率较低、占空比较大的条件下能得到更好的干扰效果。
非制冷微测辐射热计 激光损伤 功率密度 损伤等级 多晶硅 uncooled microbolometer, laser damage, power densi
Author Affiliations
Abstract
1 Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou 350002, China
2 Fuzhou University, Fuzhou 350002, China
3 Fujian Science & Technology Innovation Laboratory for Optoelectronic Information of China, Fuzhou 350108, China
4 Shanghai Institute of Ceramics, Chinese Academy of Sciences, Shanghai 200050, China
5 Collaborative Innovation Center for Optoelectronic Semiconductors and Efficient Device, Fuzhou 350108, China
End-pumped by a 976 nm diode laser, a high-repetition-rate microchip laser passively Q-switched by a crystal is reported. At a quasi-continuous-wave pump power of 20 W, a 1553 nm passively Q-switched laser with the repetition rate of 544 kHz, pulse duration of 8.3 ns, and pulse energy of 3.9 μJ was obtained. To the best of our knowledge, the 544 kHz is the highest reported value for the 1.5 μm passively Q-switched pulse laser. In the continuous-wave pumping experiment, the maximum repetition rate of 144 kHz with the pulse duration of 8.0 ns and pulse energy of 1.7 μJ was obtained at the incident pump power of 6.3 W.
1.5?μm microchip laser passive Q-switching Er:Yb:YAl34 crystal high-repetition-rate laser pulse Chinese Optics Letters
2021, 19(7): 071402
Author Affiliations
Abstract
1 College of Chemistry, Fuzhou University, Fuzhou 350108, China
2 Key Laboratory of Optoelectronic Materials Chemistry and Physics, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou 350002, China
3 Fujian Science & Technology Innovation Laboratory for Optoelectronic Information of China, Fuzhou 350108, China
4 University of Chinese Academy of Sciences, Beijing 100049, China
5 Collaborative Innovation Center for Optoelectronic Semiconductors and Efficient Devices, Fuzhou 350108, China
The behavior of self-polarization emission in lasers has been proved in some cases. However, the degree and direction of polarization were often sensitive and unstable. We experimentally observed different beam profiles versus the angle of the polarizer relative to the polarization direction of the laser. In order to explore the polarization mechanism, the dynamics of intracavity polarized eigenmodes was analyzed theoretically. Simulative results were well consistent with our experimental observations. It indicated that the linear self-polarization emission was a composite state rather than an intrinsic state. This study contributed to the improvement of the polarization stability in passively Q-switched lasers.
self-polarization emission polarized eigenmodes coherent combination Chinese Optics Letters
2021, 19(2): 021401
1 中国科学院福建物质结构研究所, 福州 350102
2 中国福建光电信息科学与技术创新实验室(闽都创新实验室), 福州 350108
3 长江大学, 荆州 434023
为测定粉末材料的紫外波段二阶非线性光学特性, 根据Kurtz-Perry粉末倍频效应理论, 开展了紫外粉末二阶非线性光学性能测试的研究。测试光源为氙灯泵浦的Nd∶YAG-KTP电光调Q激光器, KTP为二倍频晶体, 输出波长532 nm, 单脉冲能量100 mJ, 重复频率1~10 Hz, 脉冲宽度为8 ns。为保证266 nm光的透过率, 采用紫外融石英做窗口片, 型号为JGS1; 为保证测试的准确性, 选择光栅光谱仪分光。经紫外常用的KDP、LBO、BBO等测试, 证明本方法具有稳定可靠、判别精度高、操作简单等优点, 可以有效地定性或半定量测试材料的紫外二阶非线性光学性能, 为研究紫外二阶非线性光学材料提供了一种重要的测试手段。
二阶非线性光学 紫外 粉末 second-order nonlinear optic UV powder
陆军工程大学石家庄校区 电子与光学工程系，石家庄 050003
为了研究非制冷微测辐射热计的激光损伤阈值，根据非制冷微测辐射热计的构造和成像原理，分析了像元温度响应机制，推导出了零偏置下和单次偏置时间内像元受到激光辐照的温度增量计算公式；建立了激光辐照非制冷微测辐射热计的有限元分析模型，结合实际工作条件加载热源载荷进行仿真，模拟了激光造成软损伤的过程。结果表明，激光软损伤阈值可按照零偏置条件下像元温度响应的公式近似计算，其对应的温度偏差不大于3%。该研究为激光压制干扰红外成像系统的损伤阈值计算提供了参考。
光学器件 损伤阈值 有限元仿真 温度响应 optical devices damage threshold finite element simulation temperature response
