Author Affiliations
Abstract
1 Information Materials and Intelligent Sensing Laboratory of Anhui Province, Key Laboratory of Opto-Electronic Information Acquisition and Manipulation of Ministry of Education, School of Physics and Opto-electronics Engineering, Anhui University, Hefei 230601, China
2 School of Instrument Science and Opto-electronics Engineering, Laboratory of Optical Fibers and Micro-nano Photonics, Hefei University of Technology, Hefei 230009, China
3 School of Opto-electronic Engineering, Zaozhuang University, Zaozhuang 277160, China
Random lasers are a type of lasers that lack typical resonator structures, offering benefits such as easy integration, low cost, and low spatial coherence. These features make them popular for speckle-free imaging and random number generation. However, due to their high threshold and phase instability, the production of picosecond random lasers has still been a challenge. In this work, we have developed three dyes incorporating polymer optical fibers doped with various scattering nanoparticles to produce short-pulsed random fiber lasers. Notably, stable picosecond random laser emission lasting 600 ps is observed at a low pump energy of 50 µJ, indicating the gain-switching mechanism. Population inversion and gain undergo an abrupt surge as the intensity of the continuously pumped light nears the threshold level. When the intensity of the continuously pumped light reaches a specific value, the number of inversion populations in the “scattering cavity” surpasses the threshold rapidly. Simulation results based on a model that considers power-dependent gain saturation confirmed the above phenomenon. This research helps expand the understanding of the dynamics behind random medium-stimulated emission in random lasers and opens up possibilities for mode locking in these systems.
random laser polymer optical fiber gain-switched laser picosecond pulse Chinese Optics Letters
2024, 22(4): 040603
提出了一种基于聚乙烯醇（PVA）涂覆的U型超细光纤湿度传感器。光纤熔融拉锥机将单模光纤拉制成微米级的超细光纤，采用滴涂法将PVA溶液均匀的涂覆在光纤表面。为了减小传感器体积使其便于测量，将超细光纤固定为U型。实验发现，未涂覆PVA时，U型传感器的湿度灵敏度极低；涂覆PVA后，传感器在RH的检测范围内湿度灵敏度高达。温度实验表明，传感器在范围内温度灵敏度为15.8 。该传感器制备过程简单、灵敏度高、便于携带、成本低、温度串扰影响较小，在湿度检测领域有广泛的应用前景。
超细光纤 U型 聚乙烯醇 温度 湿度 Microfiber U-shaped Polyvinyl alcohol Temperature humidity 光子学报
2023, 52(12): 1206002
1 广东工业大学 机电工程学院，广州 510006
2 广州市自来水有限公司，广州 510600
光功率检测电路的性能好坏决定了接收信号的质量，介绍了光功率检测电路中半导体光电探测器的分类以及与光电探测器相连的几种常用的跨阻放大器，并根据跨阻放大器的性能指标对比了各自的优缺点和应用范围。最后，展望了光功率检测电路的发展前景。
光功率 光电探测器 跨阻放大器 检测电路 集成互补的金属氧化物半导体电路
昆明理工大学机电工程学院，云南 昆明 650500
红外光学镜头的工作环境复杂，常受到外部载荷冲击。针对某款长波红外光学镜头建立了ANSYS有限元分析模型，对其进行峰值加速度为100g、持续时间为6 ms的半正弦冲击仿真分析。对提取的数据进行刚体位移、峰谷值（PV）和均方根值（RMS）的计算，并运用泽尼克多项式对冲击之后的透镜面形进行拟合，求解泽尼克多项式系数，分析冲击对红外光学镜头性能的影响。基于响应面法对红外光学镜头进行优化，对优化之后的模型进行冲击仿真，并进行对比分析。分析结果表明：对红外光学镜头进行优化，冲击之后透镜的最大变形量与最大等效应力有所降低，表征透镜面形变化的PV、RMS也有所下降；对结构进行优化，能够在一定程度上降低冲击对其造成的影响。
长波红外光学镜头 半正弦冲击 泽尼克多项式 响应面优化 激光与光电子学进展
2023, 60(23): 2322001
昆明理工大学机电工程学院，云南 昆明 650500
硫系玻璃是热成像系统元件的重要材料，虽然适合成型，但这些脆性材料的加工特性在很大程度上是未知的。因此为了解硫系玻璃的微观变形机理，采用纳米压痕仪对硫系玻璃进行压痕实验、变载划痕实验和恒载划痕实验。纳米压痕实验中获得的数据表明，硫系玻璃在压痕的过程中出现了不连续阶梯状（pop-in）现象，从而表明材料发生了弹塑性转变，并得出材料的弹性模量和硬度；通过对压痕后的形貌进行观察，发现有边缘存在材料堆积现象，这将使通过Oliver-Pharr方法计算得出的弹性模量和硬度偏大，因此需要使用半椭圆模型进行校正。通过变载划痕实验得出划痕深度-长度曲线图，分析了硫系玻璃在每种阶段的去除方式，得出了脆塑转变的临界载荷为92.3 mN；通过对恒载划痕实验数据进行分析，得出脆塑转变的临界载荷为50~120 mN，证实了变载划痕实验所得临界载荷的准确性。
材料 硫系玻璃 纳米压痕 脆塑转变 变载划痕实验 恒载划痕实验 激光与光电子学进展
2023, 60(21): 2116002
Author Affiliations
Abstract
1 Laboratory of Optical Fibers and Micro-nano Photonics, School of Instrument Science and Opto-electronics Engineering, Hefei University of Technology, Hefei 230009, China
2 Information Materials and Intelligent Sensing Laboratory of Anhui Province, Key Laboratory of Opto-Electronic Information Acquisition and Manipulation of Ministry of Education, School of Physics and Optoelectronics Engineering, Anhui University, Hefei 230601, China
3 State Key Laboratory of Environmental Friendly Energy Materials, Southwest University of Science and Technology, Mianyang 621000, China
4 School of Opto-Electronic Engineering, Zaozhuang University, Zaozhuang 277160, China
There are many kinds of materials or methods used to make optical microcavities, and they have many different geometric structures. And electrospinning technique has become a very convenient and easy one to prepare polymer fiber. Based on this situation, PM597-doped polymer solution was prepared into high-performance fibers with different diameters by electrospinning technology in our work. In order to better study the temperature sensing of polymer fiber whispering gallery mode, we have placed it on two different substrates with gold and aluminum. A 532 nm pulsed laser beam was used to excite a single fiber in the radial direction, then the whispering gallery mode (WGM) laser was observed and the distribution of WGM was determined by theoretical calculations. The threshold of samples on aluminum substrate is 0.4 μJ. In addition, it is found that the samples on aluminum substrate performed better in temperature sensing, and the value is 0.13 nm/℃. As a result, WGM polymer fiber microcavities on aluminum substrate made by electrospinning technology have very broad development prospects in biosensing, optical pump lasers and other applications.
Whispering gallery mode gold substrate electrospinning Photonic Sensors
2022, 12(3): 220307
广东工业大学 机电工程学院, 广东 广州 510006
梯度折射率液晶透镜是一种可通过调控电场来改变其空间有效折射率分布来实现变焦的光学透镜。由于它具有焦距自由可调、结构紧凑、稳定性良好等优点, 在光学透镜领域受到了广泛的关注。本文介绍了电控梯度折射率液晶透镜的基本工作原理, 描述了4种电极类型的梯度折射率液晶透镜: 边缘电场驱动的液晶透镜、离散多电极型液晶透镜、高阻层电极型液晶透镜、完整电极或无电极层液晶透镜。通过评价具有代表性的例子全面地展示液晶透镜的发展现状, 读者可简单、清晰, 直观地了解和掌握电控折射率液晶透镜的发展历程与未来方向, 为进一步研究电控梯度折射率液晶透镜提供清晰的基础认知与参考方向。
电场控制 液晶 光学透镜 梯度折射率 electric field control liquid crystal optical lens gradient index
1 广东工业大学 机电工程学院, 广州 510006
2 广州市自来水有限公司, 广州 510600
半导体脉冲激光器的结构、材料、加工工艺和驱动电源特性是其性能的重要影响因素, 结合脉冲宽度、输出功率和重复频率等技术指标, 综述了半导体脉冲激光器的发展与研究现状, 着重介绍了窄脉冲叠加直流偏置法、储能元件的应用、高速开关的级联或阵列、可编程逻辑器件的应用以及器件选型和布局创新这5种驱动电源性能提升方式, 并指出目前技术存在的不足。最后, 对半导体脉冲激光器的发展趋势进行了展望。
半导体脉冲激光器 脉冲宽度 输出功率 重复频率 驱动电源 semiconductor pulsed laser pulse width output power repetition frequency driving power
Author Affiliations
Abstract
1 State Key Laboratory of Precision Electronic Manufacturing Technology and Equipment, School of Electromechanical Engineering, Guangdong University of Technology, Guangzhou 510006, China
2 Wuhan National Laboratory for Optoelectronics & School of Optical and Electronic Information, Huazhong University of Science and Technology, Wuhan 430074, China
3 Institute of Photonic and Technologies, Aston University, Birmingham B4 7ET, UK
We propose and demonstrate a sensitive vector twist sensor based on a small period long period fiber grating (SP-LPFG) fabricated with a femtosecond (fs) laser. The fabricated SP-LPFG is compact in size (2.8 mm) and shows strong polarization dependent peaks in its transmission spectrum due to the vectorial behavior of high-order cladding modes. Twist sensing is realized by monitoring the polarization dependent peaks, since the polarization of input light changes with fiber twist. The proposed sensor can be interrogated by the peak intensity and wavelength, with high twist sensitivity that reaches 0.257 dB/deg and 0.115 nm/deg, respectively.
fiber optical sensor long period fiber grating twist sensor Chinese Optics Letters
2021, 19(9): 090601
