Author Affiliations
Abstract
1 Center for Optics Research and Engineering, Key Laboratory of Laser & Infrared System, Ministry of Education, Shandong University, Qingdao 266237, China
2 School of Information Science and Engineering, Shandong University, Qingdao 266237, China
3 e-mail: yunzheng_wang@sdu.edu.cn
4 e-mail: junlei.wang@sdu.edu.cn
Dynamic infrared thermal camouflage technology has attracted extensive attention due to its ability to thermally conceal targets in various environmental backgrounds by tuning thermal emission. The use of phase change materials (PCMs) offers numerous advantages, including zero static power, rapid modulation rate, and large emissivity tuning range. However, existing PCM solutions still encounter several practical application challenges, such as temperature uniformity, amorphization achievement, and adaptability to different environments. In this paper, we present the design of an electrically controlled metal-insulator-metal thermal emitter based on a PCM metasurface, and numerically investigate its emissivity tunability, physical mechanisms, heat conduction, and thermal camouflage performance across different backgrounds. Furthermore, the influence of the quench rate on amorphization was studied to provide a guidance for evaluating and optimizing device structures. Simulation results reveal that the thermal emitter exhibits a wide spectral emissivity tuning range between 8 and 14 μm, considerable quench rates for achieving amorphization, and the ability to provide thermal camouflage across a wide background temperature range. Therefore, it is anticipated that this contribution will promote the development of PCM-based thermal emitters for practical dynamic infrared thermal camouflage technology with broad applications in both civilian and military domains.
Photonics Research
2024, 12(2): 292
1 中国计量学院光学与电子科技学院, 浙江 杭州 310018
2 北京安伟联创科技有限公司, 北京 100081
马赫-曾德尔调制器的工作特性随温度变化等环境因素影响严重，因此需要设计专用的偏置电压控制电路。利用扰动输入和谐波探测相结合的偏置电压控制方案是一种比较好的解决方案，但传统的控制架构在面对大调制信号输入时，往往会出现锁定点严重漂移的现象。首先对谐波产生的机制的进行了理论建模，然后对传统的谐波检测架构进行了分析，发现大信号调制下的以往谐波分量计算公式以不再适用，必须加以改进，因此在改进谐波计算公式的基础上，提出了一种新的可用于大信号调制下的偏置点控制技术，并研制了相应的驱动电路，对电路的偏置点控制测试结果发现，提出的方案偏置点的控制精度在1°以内，可以很好地满足大调制信号输入的应用需求。
光学器件 马赫-曾德尔调制器 偏置电压控制 谐波 大调制信号
Author Affiliations
Abstract
A passively Q-switched tunable Yb-doped double-clad fiber laser is demonstrated with graphene epitaxially grown on SiC. The spectral tuning of the Q-switched fiber laser is implemented by rotating a quartz plate filter inside the cavity. The central wavelength of the fiber laser can be continuously tuned from 1038.54 to 1056.22 nm. The maximum pulse energy of 0.65 \mu J is obtained at the pump power of 4.08 W, and the corresponding pulse duration and average output power are 1.60 \mu s and 35 mW, respectively.
140.3540 Lasers, Q-switched 140.3510 Lasers, fiber 140.3600 Lasers, tunable 140.3538 Lasers, pulsed Chinese Optics Letters
2014, 12(2): 021405
1 山东大学信息科学与工程学院, 山东 济南 250100
2 济南山信光电科技有限公司, 山东 济南 250100
基于耦合的Ginzburg-Landau方程和各器件的琼斯矩阵，建立了全正色散锁模光纤激光器的数值模型，计算了腔内各点脉冲不同部分的偏振态。计算结果表明，当线性双折射较强时，光纤中脉冲的偏振态近似以拍长为周期变化，一个拍长内的演化过程为右旋椭圆偏振光线偏振光左旋椭圆偏振光线偏振光右旋椭圆偏振光。与一般的饱和吸收体不同，非线性偏振旋转等效饱和吸收体的调制深度随波片角度变化。计算了波片方位角改变时，调制深度的变化情况。相比于偏振分束器之前的1/2波片及1/4波片，偏振分束器之后的波片对调制深度的影响更大。
激光器 光纤激光器 锁模 非线性偏振旋转 全正色散
Author Affiliations
Abstract
The fluorescence spectrum and thermal properties of the mixed crystal Nd:Lu0.99La0.01VO4 are determined. The strongest emission peak located at 1065.6 nm had a full width at half maximum (FWHM) of 2.1 nm. Continuous-wave (CW) laser performance is demonstrated by a compact planar–planar cavity that is endpumped by a diode laser. The laser output characteristics are investigated by using output couplers with different transmissions. A maximum CW output power of 8.09 W was obtained at an incident pump power of 19.4 W, which corresponds to an optical-to-optical conversion efficiency of 41.7% and a slope efficiency of 54.6%. The dependence of optimum transmission on pump power is calculated theoretically and is found to be consistent with experimental results.
140.3380 Laser materials 350.6830 Thermal lensing 140.3480 Lasers, diode-pumped 140.3580 Lasers, solid-state Chinese Optics Letters
2013, 11(12): 121404
1 山东大学信息科学与工程学院, 山东 济南 250100
2 中国电子科技集团公司第二十三研究所, 上海 201900
以双包层掺镱光纤为增益介质，双折射滤光片为波长选择器件，搭建了可调谐耗散孤子锁模光纤激光器。通过旋转滤光片，激光器的输出波长在1063.9～1091.1 nm范围内连续可调，脉冲宽度及光谱带宽的变化范围分别为13.9～16.8 ps和15.8～18 nm。中心波长为1063.9 nm时，激光器输出功率为212 mW，单脉冲能量为8.5 nJ。基于耦合的Ginzburg-Landau方程和各器件的琼斯矩阵，建立了可调谐耗散孤子锁模激光器的数值模型，对激光器的可调谐性能进行模拟，模拟结果与实验结果一致。
激光器 波长调谐 耗散孤子 双包层光纤 锁模 中国激光
2013, 40(12): 1202007
1 山东大学 信息学院，济南 250100
2 山大鲁能中晶公司，济南 250100
为了分析影响双块晶体电光开关消光比的各项因素，采用折射率椭球方法，进行了理论分析和实验验证。结果表明，两晶体通光方向偏差及偏振器件透振方向偏差对消光比影响较大，只要仔细调解上述两方面就能实现较好的电光调Q效果。
光学器件 消光比分析 折射率椭球法 双晶体 optical devices contrast-ratio analysis index-ellipsoid method double crystals
Author Affiliations
Abstract
1 College of Physics and Electronics, Shandong Normal University, Ji'nan 250014
2 Shanda Luneng Information and Technology Co., Ltd., Shandong University, Ji'nan 250100
Thermal effects control is very critical in highly scaling the output power of diode-pumped solid-state lasers to a few watts especially for end pumping configuration. Low temperature reservation of the pumping surface and the crystal could be adopted to reduce thermal effects and improve laser performance. Diffusion bonding crystal has been demonstrated to be an effective method to relieve the thermal lensing theoretically based on the numerical heat analysis to the end-pumped anisotropic laser crystal. The temperature distribution in Nd:YVO4/YVO4 composite crystal was analyzed before the end-pumped Nd:YVO4/YVO4 composite crystal laser with V cavity was designed and set up. The maximum output powers of 9.53 W at 1064 nm, 5.01 W at 532 nm were obtained while the pumping power was 17 W. The highest optical to optical conversion efficiencies were up to 59.1% at 1064 nm and 34.4% at 532 nm, respectively.
140.3480 Lasers, diode-pumped 140.3380 Laser materials 140.6810 Thermal effects 190.2620 Harmonic generation and mixing Chinese Optics Letters
2007, 5(s1): 13
Author Affiliations
Abstract
1 College of Physics and Electronics, Shandong Normal University, Ji'nan 250014
2 Shanda Luneng Information and Technology Co., Ltd., Shandong University, Ji'nan 250100
3 College of Information Science and Engineering, Shandong University, Ji'nan 250100
Thermal effect in crystals is the main obstacle blocking diode-pumped solid state laser to get high and stable output power. Diffusion bonding crystal has been demonstrated to be an effective method to relieve the thermal lensing theoretically based on the numerical heat analysis to the end-pumped anisotropic laser crystal. The temperature distributions in Nd:YVO4/YVO4 composite crystal and conventional crystal were analyzed and compared. The end-pumped Nd:YVO4/YVO4 composite crystal laser was designed and set up with z-cavity. The maximum output powers of 9.87 W at 1064 nm and 6.14 W at 532 nm were obtained at the incident pump power of 16.5 W. The highest optical-optical conversion efficiencies were up to 59.8% at 1064 nm and 37.2% at 532 nm respectively.
激光器 端面抽运 Nd:YVO4/YVO4复合晶体 数值方法 热效应 140.3480 Lasers, diode-pumped 140.3380 Laser materials 140.6810 Thermal effects 190.2620 Harmonic generation and mixing Chinese Optics Letters
2007, 5(3): 175
1 山东师范大学物理与电子科学学院，济南 250014
2 山大鲁能科技有限责任公司，济南 250100
3 中国科学院半导体研究所，北京 100083
4 天津大学精密仪器与光电子工程学院超快激光实验室，天津 300072
采用一种新型的被动调Q饱和吸收体，低温生长GaAs薄膜，实现了半导体抽运Nd∶YVO4激光器的调Q运转．研究了激光器的调Q特性，调Q抽运阈值为2W．在抽运功率9．2 W时，获得的最短脉冲半峰全宽为15ns，最大单脉冲能量为4．84μJ，最高峰值功率为330 W，最大平均输出功率为1．16 W；脉冲重复频率在220 kHz到360 kHz之间．
低温生长GaAs 被动调Q Nd∶YVO4激光器 半导体抽运 GaAs grown at low temperature Passive Q-switch Nd∶YVO4 laser Laser diode pumping
