BIREFRINGENCE AND OPTICAL-ACTIVITY OF SINGLE-CRYSTAL CDAS2 IN THE INFRARED

The dispersion of the refractive indices and the optical activity of s ingle-crystal CdAs2 in the IR is studied. It is shown that CdAs2 cryst als possess high optical transmittance in the 1.15-25-mum wavelength i nterval, in conjunction with a sharp edge in the fundamental absorptio n region, significant birefringence, and giant gyrotropy. The quantity DELTAn = n(e) - n0 reaches 0. 36 at lambda = 1.3 mum. As wavelength i ncreases, DELTAn monotonically decreases to 0.3 at lambda = 10 mum, an d afterwards is virtually constant. Gyrotropy rho amounts to 3 rad/mm at lambda = 1.2 mum.