基底对光学薄膜弱吸收测量的影响

对表面热透镜技术测量光学薄膜弱吸收低频调制时不同基底对测量的影响进行了理论分析。用Lambda-900分光光度计测量了K9和石英基底的Ti3O5单层膜的吸收值，将该组样品作为定标片；用表面热透镜装置分别测量了BK7和石英空白基底及HfO2，ZnO两组不同基底不同厚度单层膜样品的吸收。通过分析比较同一工艺条件下镀制的不同基底薄膜样品用与其同种和不同种基底定标片定标测量的结果，表明在低频测量时需要用与测量样品同种基底的定标片定标；不同厚度样品的测量结果表明，在不能严格满足热薄条件时，测量结果需引入修正值。

abstract {The substrate effects on the measurement of weak absorption of optical thin films at low frequency are analyzed in theory. The absorptions of different thin films, including single-layer HfO₂ and ZnO thin films with different thickness, on two substrates (BK7 and silica), as well as absorptions of blank substrates have been measured by surface thermal lensing technique. As a calibrated sample, the absorptions of singal-layer Ti₃O₅ thin films were measured by Lambda-900 spectrometer. The experimental results show that the substrate of standard film is the same as the substrate of sample in calibration for low measurement is necessary. After considering the influence of film thickness, the correction would be possible.}