1 北京理工大学光电学院，北京 100081
2 昆明物理研究所，云南昆明 650217
为改善 Ge基底红外长波增透膜的耐恶劣环境性，研究了 LaF3晶体作为低折射率材料的膜系设计过程和制备工艺。通过优化膜系结构和分段制备 LaF3层技术获得了高光学性能的多层增透膜。在 8～ 12 .m波段，峰值透过率达到 98.3%，双面镀膜平均透过率从 48.4%提高到 96.2%。力学性能、环境试验结果显示，基于 LaF3材料的长波高效增透膜在保持高的光能量透过的同时还可以经受较为恶劣的环境测试。
长波红外 高性能增透膜 LaF3 LaF3，long wave infrared band，high performance an
1 北京理工大学 光电学院, 北京 100081
2 北方夜视科技集团有限公司, 云南 昆明 650221
研究了LaF3材料的蒸发特性及其在2.5~12 μm红外波段的光学常数, 并将LaF3晶体作为低折射率材料在Ge基底上制备了中波红外3.7~4.8 μm波段高耐用性增透膜。SEM照片显示, 基于LaF3材料的高耐用性增透膜表面纳米晶粒分布均匀致密, 表面光洁度高。利用傅里叶变换红外光谱仪测试了其光谱特性, 在3.7~4.8 μm波段, 峰值透射率达到99.4%, 双面镀膜平均透射率由47.7%提高到98.8%。牢固度、耐久性等环境试验结果显示, 膜层在保持高的光学性能的同时还可以在较为严苛的恶劣环境中使用
高耐用性 增透膜 中波红外 LaF3 LaF3 high durability antireflective film medium-wavelength infrared 红外与激光工程
2019, 48(11): 1117001
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
