Author Affiliations
Abstract
1 Beijing Key Laboratory of Nanophotonics and Ultrafine Optoelectronic Systems, Key Laboratory of Photoelectronic Imaging Technology and System, Ministry of Education, School of Optics and Photonics, Beijing Institute of Technology, Beijing 100081, China
2 Yunnan KIRO - CH Photonics Co., Ltd., Kunming 650223, China
3 School of Materials Science & Engineering, Beijing Institute of Technology, Beijing 100081, China
A gradient-index Reuleaux-triangle-shaped hole array was fabricated on germanium (Ge) by nanoimprint lithography and inductively coupled plasma processing as a broadband mid-infrared (IR) antireflective surface. The interaction between the {111} planes of cubic crystalline Ge and a circular mold successfully produced an orderly and periodically distributed Reuleaux-triangle-shaped hole array. As a result, the average transmittance increased 15.67% over the waveband at 3–12 μm and remained stable at the incidence angle of up to 60°. The vertices of the Reuleaux triangle showed local enhancement of the electric field intensities due to interference of the incident and reflected radiation fields. It was also found that nonuniform hole depths acted to modulate the transmittance over the 3–12 μm waveband.
240.6700 Surfaces 160.4670 Optical materials Chinese Optics Letters
2019, 17(12): 122401
1 北京理工大学 光电学院, 北京 100081
2 北京理工大学珠海学院 信息学院, 广东 珠海 518088
为了改善不同类型光纤熔接时的模场失配, 通过调整普通光纤熔接机的熔接参数, 对模场直径较小的光纤进行加热扩芯, 实现了10/130μm大模场面积双包层光纤和6/125μm单模光纤的低损耗熔接, 光纤耦合效率可达到91%, 并成功应用于自主研发的小型1064nm光纤激光器中。对利用光纤熔接机加热扩芯制作模场适配器进行了理论分析, 并用1064nm光纤激光器测量其实际传输损耗。实验结果表明: 采用普通光纤熔接机, 适当的调整熔接参数, 可以有效地提高大模场面积光纤到单模光纤的耦合效率, 为制作模场适配器提供了一种简单实用的方法。
激光技术 模场适配器 加热扩芯 光纤熔接损耗 laser technology mode-field adaptors thermally expanded core(TEC) loss of fiber fusion splicing
1 北京理工大学光电学院, 北京 100081
2 北京理工大学珠海学院信息学院, 广东 珠海 519088
针对环形激光谐振腔的光路变动的问题，基于SolidWorks 建立了一个两平面镜和两凹面镜构成的四镜8 字形稳定环形激光谐振腔模型。使用该方法分析了腔镜水平移动、垂直移动和绕光轴旋转对光路的影响，可以简单直观地观察到腔内光路的变化，并获得调节容差，模拟过程更加接近环形腔实际调节过程。当增大晶体和腔镜M1 之间的距离L 时，可以提高腔镜M2 的水平位移容差，但角度容差有所降低，垂直容差变化不大。水平位移容差和角度容差有较强的耦合关系，腔镜水平方向的微动往往可以通过改变角度来补偿。所得到的结果对于腔设计、腔调节以及提高腔的精度具有重要的指导作用，同时可以推广到对三角形腔、正方形腔以及非平面环形腔等谐振腔的容差分析当中。
激光器 环形激光谐振腔 位移容差 角度容差 激光与光电子学进展
2016, 53(3): 031404
