Cs2HgCl4 crystal as a new material for acoustooptical applications

Abstract

The paper reports the basic acoustical (anisotropy of phase velocity Vi and obliquity angle θ), optical (transparency spectra, refractive indices ni and photoelastic constants pij) and acoustooptical (figure of merit M2 = pef2ñ6/ρV3) parameters of Cs2HgCl4 crystals that are necessary for a design of acoustooptical devices. Substantial photoelastic effect (pij ∼ 0.17-0.41 for i,j = 1-3) and low ultrasonic velocities (Vi ∼ 870-2500 m/s) in Cs2HgCl4 crystals determine relatively high figure of merit M2 for the isotropic acoustooptical diffraction. We have found that for certain geometries of acoustooptical interactions M2 ∼ (85-114) × 10-15 s3/kg. The new material may be considered, therefore, as a candidate for applications in acoustooptical devices. © 2002 Elsevier Science B.V. All rights reserved.