Low-loss short-wavelength optical waveguides using ZnSe-ZnS strained-layer superlattices

Abstract

Low-loss short-wavelength optical ridge waveguides using ZnSe-ZnS strained-layer superlattices (SLS’s) were successfully fabricated on GaAs substrates by low-pressure metalorganic vapor phase epitaxy. A propagation loss α as low as 0.71 cm−1 was obtained for the SLS waveguide composed of 80 periods of ZnSe(50 Å)-ZnS(50 Å) at the 0.633-μm wavelength TE fundamental mode. Therefore, this waveguide may be suited for optoelectronic integrated circuits composed of II-VI and III-V compound semiconductor devices. Furthermore, these waveguides exhibited a large difference in the propagation loss between TE and TM polarizations which may be related to the birefringence for TE and TM polarizations due to the slight anisotropy of the refractive index in the ZnSe-ZnS superlattice structure. This birefringence effect will be very useful for a polarizing optical device.