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
GaN基脊型激光二极管(LD)的制备工艺中, 面临的一个主要困难是p电极和窄脊结构的制备受到光刻对准精度的严重制约。设计和验证了一种基于背向曝光技术的激光器制备工艺。通过预先沉积一层200nm的铝作为挡光掩模和牺牲层, 利用ICP蚀刻制备出宽为2.5μm的脊型结构, 并使用PECVD沉积SiO2绝缘层。随后采用背向曝光实现二次光刻, 将脊型图形精确地转移到电极窗口, 继而采用湿法腐蚀SiO2绝缘层打开窗口, 借助对的铝掩模腐蚀实现对残余绝缘层的辅助剥离, 从而同时解决了目前脊型激光器电极窗口对准困难和绝缘层侧向腐蚀条件难于把握的问题。
激光器 脊型 背向曝光 掩埋金属层 laser diode ridge backward exposure buried metal mask
