Characterization of Response of ZnO/LiNbO3-Based Surface Acoustic Wave Delay Line Photodetector

In this study. the coupling-of-mode simulation is applied to the characterization of the optical response Of a Surface acoustic wave (SAW) photodetector. To verify the simulation results, a ZnO/LiNbO3-based SAW delay line without an oscillator and amplifier circuit is fabricated. The ZnO/LiNbO3 bilayer is proved to be a good UV-light-sensing structure where bulk LiNbO3 is used to excite the Surface wave and the ZnO overlayer is a photosensitive layer. The measurement of insertion loss difference is used to clarify optical perturbation in detail. The Simulation and experimental responses show a good agreement. From the measurement results of insertion loss difference, the optical characteristics (i.e., optical spectrum, dynamic responses and thermal properties) of the SAW delay line are also determined.