Broadband Acousto-Optic Modulation of Optical Radiation

Abstract

Abstract—For broadband modulation of the intensity of optical radiation, the tandem arrangement two acousto-optic (AO) Bragg cells are proposed in which acoustic waves propagate in opposite directions. The device allows modulation of optical radiation in the acoustic frequency band of ~6 MHz at four times the frequency of the sound. The possibility of switching the modulation frequency from 2f to 4f, where f is the frequency of sound, by simply turning the output polarizer is demonstrated. The method is experimentally tested for modulating radiation with a wavelength of 0.63 × 10^–4 cm using two AO cells made of paratellurite operating at a center frequency of 22 MHz.