Some ternary groups 1VA‐VA‐V1A nonoxide glasses have been found which have very low acoustic losses of the order of fused silica, low values of sound velocity, and very high acousto‐optic figures of merit. Their optical transmission range is 1 – 12&mgr;. The unusual combination of these parameters in a chemically stable isotropic medium make these glasses attractive for us in acoustic and acousto‐optic devices operating at infrared wavelengths.