Acousto-optic filters based on the superposition of diffraction fields [Invited]

Abstract

Methods for the calculation of the acousto-optic (AO) transfer functions forming as a result of superposition of two AO fields with similar and orthogonal light polarizations are proposed. Specific calculations are made on the basis of the parameters widely used in practice with uni-axial gyrotropic crystal paratellurite. It is revealed that the resulting field is generally very inhomogeneous but contains domains with two-dimensional behavior properties. These domains can be used for two-dimensional image edge enhancement based on Fourier processing. Theoretical conclusions are verified by means of the optical image Fourier processing with the spatial frequency AO paratellurite filters.

Acousto-Optic Transfer Function Control by a Phased-Array Piezoelectric Transducer

“…In this case, the amplitude of the first sidelobe becomes equal to the amplitude of the main maximum. Analysis of Equation (7) shows that at ∆φ = ±π, the maximum of T 1 = 1 takes place at H = ∓ √ 2 and Q = √ 2. In between, the increase in the phase delay has two main effects.…”

“…The following step of the simulation is to take into account the spatial structure of phase matching. The phase mismatch η has be calculated for a certain diffraction geometry and substituted into Equation (7). Under the condition of anisotropic Bragg diffraction in a uniaxial crystal, which is used in noncollinear AOTFs, it can be written as follows [2]:…”

“…AOTFs directly filter the angular spectrum of laser beams, as first shown by Balakshy [4]. Based on special phase-matching conditions in birefringent crystals, acoustooptic spatial filters (AOSFs) can provide a variety of transfer functions [5][6][7][8][9]. There are several fundamental topologies of an AOSF's transfer function, which are determined by the curvature tensor of the optical wave normal surface [10].…”

Optical image processing using acousto-optic modulators as programmable volume holograms: a review [Invited]

“…Some recent publications involving anisotropic Bragg processing include the works in Refs. [21][22][23][24][25][26][27].…”

Acoustooptic Diffraction of Three-Color Radiation on a Single Acoustic Wave

“…The calculations were made for the acoustic frequency 148 MHz and angle of incidence = 4.02 ∘ . By taking into account the crystal gyrotropy the refractive indices of the crystal are described by [17]:…”