Modal control in semiconductor optical waveguides with uniaxially patterned layers

Uniaxially patterned (UAP) dielectric layers have an optical anisotropy that can be externally controlled. This paper examines the effects of patterning the cladding or the core layer of a three-layer optical waveguide on the polarization properties of propagating radiation. Particular attention is paid to the case when the core material is a semiconductor with optical gain. A number of devices are discussed based on incorporating a UAP layer in the structure design, such as a polarization-insensitive amplifier, a polarizer, an optically controlled polarization switch, and an optically controlled modal coupler.