Amplification of Acoustic Wave in GaN in the Presence of Slowly Changing Periodic Electric Field

Abstract

Acoustic wave propagation in bulk GaN Semiconductor in the presence of a slowly changing a.c electric field and a constant electric field has been studied. Analytical expression for the attenuation (amplification) coefficient has been obtained. It is shown that the a.c electric field is acting as a modulator and that the acoustoelectric gain increases to a maximum value and then fall off as the acoustic wave frequency is increased. Also for a a.c electric field of 4 x 104 V/CM the acoustoelectric gain remains zero until the acoustic wave frequency is about 5.8x1012Hz then a resonant amplification peak appears. If the a.c electric field is increased a second resonant peak accurs at 8.7x1012Hz. It is therefore suggested that the sample can be used as a maser.