Infrared waveguides in thin films of CdS

Laser radiation at 1.15 μm has been guided in thin films of CdS which were evaporated onto both glass and quartz substrates in a UHV system. The infrared radiation was coupled into and out of the films by both prisms and ion-etched gratings, and a minimum propagation loss for the TE0 mode of less than 5 dB cm−1 was measured. A small birefringence was observed in these experiments, Δn = nTM − nTE≃0.01.