Optical mode properties of laterally offset gain and index guiding structures

We describe the mode properties of offset gain and index guided structures in which gain and index guiding effects are simultaneously present and oriented in parallel but laterally offset. Such structures can occur in semiconductor lasers, integrated optics, and optical waveguides. Within the parabolic approximation the resulting waveguide modes are found to be Hermite-Gaussian functions with complex-valued Gaussian mode parameters and centerlines. The lateral positions and far-field angles of these modes can be controlled by modifying the gain and index guiding parameters, permitting both transverse mode displacement and output beam steering