双离子束溅射制备近红外窄带通滤光片的光谱和表面形貌

Optical Spectra and Surface Morphologies of Near-Infrared Narrow Band-Pass Filters Using Dual Ion Beam Sputtering

为了观测大气层中的水汽含量以及CH4和CO2的浓度,在蓝宝石(Al2O3)基片上制备了两种窄带通滤光片,其中心波长分别为1375nm和1610nm,带宽分别为15nm和60nm,透过率均达到了95%。基于法布里-珀罗腔结构设计了带通滤光膜系,并对其进行了优化。与电子束蒸镀薄膜相比,采用双离子束溅射沉积方法制备的Nb2O5/SiO2滤光片薄膜,其表面质量明显改善,缺陷减少,表面粗糙度均方根降低到1nm以下,显著改善了与光电探测器光耦合时的不均匀性。

To investigate water vapor, methane (CH4), and carbon dioxide (CO2) concentrations in the atmosphere, two near-infrared narrow band-pass filters are fabricated on sapphire substrates. The central wavelengths are 1375 nm and 1610 nm and bandwidths are 15 nm and 60 nm, with average transmission of 95%. Nb2O5/SiO2 Fabry-Perot multilayer filters are optimized and deposited using dual ion beam sputtering. Compared to electron beam evaporated films, the dual ion beam sputtered films have significantly improved surface quality and reduced defects, and their root-mean-square surface roughness is reduced to below 1 nm, which significantly improves the uniformity of electric signals when coupled with a photodetector.