Analysis of pyroelectric signal in photoacoustic spectroscopy using a transparent transducer

It is shown that a pyroelectric signal from a transparent transducer, Z -cut LiNbO 3 , depends on the surface state of the measured sample, a Si wafer. The signal of the Si wafer with the native oxide deviates markedly from the normal pyroelectric signal. Also, we develop a three-dimensional theory of 1he transparent pyroelectric transducer method in photoacoustic spectroscopy (PAS). We discuss the cases in which the pump beam illuminates the sample not only directly, but also through the transducer. It is shown that the theoretical calculation results are in good agreement with the experimental data of both PA amplitude and phase signals of Si. This result indicates that the validity of our theoretical model is verified experimentally.