【摘要】 本文以“一维热流活塞模型”为基础,推导出薄膜光声表达式,光声信号的幅值正比于吸收率.测量了透明基底上光学薄膜的光声吸收谱,实验结果与理论一致.尤其是测量弱吸收薄膜的吸收谱时,具有较高的灵敏度和实用性.更多还原

【Abstract】 Considering the absorption taking place during the back and forth passages inside of the opticl films, and the optical films being "thermally thin" in photoacoustics, a photoacoustic expression for optical thin films is deduced according to the one-dimensional heat-flow piston model. The amplitude of photoacoustic signal is proportional to the absorptivity of the film. Some photoaooustio absorption spectra of films on glass are measured, which is in agreement with the theoretical expressoin. This photoacoustic spectral method shows high sensitivity and precision, particularly uitable for measuring the absorption spectra of weakly absorbing films.更多还原