Successive diffraction model based on Fourier optics as a tool for the studies of light interaction with arbitrary ultrasonic field

Abstract

In this paper we presented theoretical predictions of light diffraction by complex acoustic fields such as: two adjacent and superposed ultrasonic beams or ultrasound of cylindrical symmetry. The numerical calculations of light intensity of diffraction orders were performed by means of two methods: Nth Order Approximation (NOA) and Successive Diffraction Model (SDM) based on Fourier optics. The latter technique involves dividing the ultrasonic field into several adjacent sections provided that in each section the interaction of light and ultrasound is considered to fulfill Raman-Nath approximation. Propagation of light inside and behind the region with ultrasonic wave was described within the formalism of Fourier optics so that only both transfer and transmission functions had to be appropriately defined. It was revealed that SDM method based on Fourier optics might be applied in the studies of acousto-optic interaction in the cases of complex ultrasonic fields.