Si薄膜在可见光和近红外波段具有一定的吸收特性, 可用于宽带吸收薄膜的制备。采用离子束溅射技术, 在熔融石英基底上制备了不同沉积工艺参数的Si薄膜, 基于透、反射光谱和椭偏光谱的全光谱数值拟合法, 计算了Si薄膜的光学常数, 并研究了氧气、氮气流量对其光学特性的影响。选择Si和Ta2O5作为高折射率材料、SiO2作为低折射率, 设计了吸收率为2%和10%的宽带(1 000~1 400 nm)吸收薄膜。采用离子束溅射沉积技术, 在熔融石英基底上制备了宽带吸收薄膜, 对于A=2%的宽带吸收光谱, 在1 064、1 200、1 319 nm的吸收率分别为2.12%、2.15%和2.22%; 对于A=10%的宽带吸收光谱, 在1 064、1 200、1 319 nm的吸收率分别为9.71%、8.35%和9.07%。研究结果对于吸收测量仪、光谱测试仪等仪器的定标具有重要的作用。

Si thin film has certain absorption characteristics in visible and near-infrared bands and can be used for preparing broadband absorption film. Si thin films were deposited on fused silica substrate with different deposition process parameters by ion beam sputtering technology. Based on full spectrum numerical fitting methods with the transmission spectra, reflection spectra, and ellipsometry spectra, optical constants of Si thin films were calculated. The effects of oxygen and nitrogen flow rate on optical properties were also researched. Choosing Si and Ta2O5 thin film as high refractive index materials and SiO2 thin film as low refractive index material, broadband (1 000-1 400 nm) absorption films with the absorption rate of 2% and 10% were designed. Using ion beam sputtering technique, broadband absorption films were deposited on the fused silica substrates. For broadband absorption film (A=2%), the absorption rate at the wavelength of 1 064, 1 200 and 1 319 nm were respectively 2.12%, 2.15% and 2.22%. For broadband absorption film(A=10%), the absorption rate at the wavelength of 1 064, 1 200 and 1 319 nm were respectively 9.71%, 8.35% and 9.07%. The results are of great importance to the calibration of instrument such as absorption measuring instrument and spectroscopic instrument.