Tl3 PSe4 Compound, single crystals, and acousto-optical devices

Abstract

The compound Tl 3 PSe 4 is disclosed. Non-conducting single crystals of the compound are prepared which have outstanding acousto-optical properties including an exceptionally high acousto-optical figure of merit. The crystals are used in various acousto-optical devices including a display device, a laser modulator, a non-collinear acousto-optic filter, and an acoustic delay line.

We claim: 
     
       1. A compound having the general formula Tl 3  XSe 4  where X is about 50 to about 100% phosphorus and about 0 to about 50% arsenic. 
     
     
       2. A single crystal of the compound of claim 1. 
     
     
       3. A compound according to claim 1 having the formula Tl 3  PSe 4 . 
     
     
       4. A biaxial, non-piezoelectric orthorhombic single crystal according to claim 2 having the formula Tl 3  PSe 4 . 
     
     
       5. A single crystal according to claim 2 which is at least about .[.10 -3  .]. .Iadd.0.05 .Iaddend.cm .[.wide.]. .Iadd.in diameter .Iaddend.and .Iadd.at least about .Iaddend.1 .[.mm.]. .Iadd.cm .Iaddend.long. 
     
     
       6. A single crystal according to claim 5 which is at least about 0.5 cm in diameter and at least about 1 cm long. 
     
     
       7. A single crystal according to claim 5 having two parallel optical faces.