New materials for highly efficient acoustooptical operation of high power laser radiation

Abstract

Summary form only given. The optical (refractive indices, piezooptic coefficients, optical damage thresholds and the transmission spectra) and the elastic properties of the /spl alpha/-BaB/sub 2/O/sub 4/, /spl beta/-BaB/sub 2/O/sub 4/, Li/sub 2/B/sub 4/O/sub 7/ and CsLiB/sub 6/O/sub 10/ crystals are investigated. It is shown that these crystals possess wide range of transparency (/spl sim/0.2 - 3 /spl mu/m) and high level of the optical damage threshold (e.g. for Li/sub 2/B/sub 4/O/sub 7/ it is 32.2 GW/cm/sup 2/). The components of the elastic matrix C/sub mn/ of these crystals are calculated on the basis of the ultrasonic velocity measurements. The photoelastic coefficients of the borate crystals are calculated on the basis of piezooptical coefficients measured with interferometric technique. Using the determined values of the refractive, elastic and photoelastic tensor components, we have calculated the values of the acoustooptic figure of merit M/sub 2/ for these crystals. The acoustooptical figure of merit of /spl alpha/-BaB/sub 2/O/sub 4/ and LiB/sub 4/O/sub 7/ crystals achieve value M/sub 2/ = 243.4 /spl times/ 10/sup -15/ s/sup 3//kg and M/sub 2/ = 2.57 /spl times/ 10/sup -15/ s/sup 3//kg at the interaction with the slowest ultrasonic waves /spl nu/ = 933.5 m/s and /spl nu/ = 3173 m/s, respectively. The acoustooptical modulators on the base of /spl alpha/-BaB/sub 2/O/sub 4/ and LiB/sub 4/O/sub 7/ crystals have been constructed and performance characteristics have been obtained experimentally.