Acoustic Velocity and Optical Index Birefringence in A-Plane ZnO Thin Films

Abstract

The longitudinal acoustic velocity in the direction normal to the c-axis and the birefringence of refractive index of a-plane zinc oxide (ZnO) thin films were measured by ultrafast transient reflection measurement. Through Fourier analysis, the experimental data show that the acoustic velocity is about 6000 m/s and the measured refractive index near the band gap, which is higher than the previously reported results by 20 similar to 30%.