METHOD AND APPARATUS FOR SUPPRESSION OF SPATIAL-HOLE BURNINGIN SECOND OR HIGHER ORDER DFB LASERS

摘要

A surface emitting semiconductor laser is shown having a semiconductor laser structure defining an intrinsic cavity having an active layer, opposed cladding layers contiguous to said active layer, a substrate and electrodes by which current can be injected into said semiconductor laser structure to cause said laser structure to emit an output signal in th e form of at least a surface emission. The intrinsic cavity is configured to have a dominant mode on a longer wavelength side of a stop band. A structure such as a buried heterostructure for laterally confining an optical mode is included. A second order distributed diffraction grating is associated with the intrinsic cavity, the diffraction grating having a plurality of grating elements having periodically alternating optical properties when said current is injected into said laser structure. The grating is sized and shaped to generate counter-running guided modes within the intrinsic cavity wherein the grating has a duty cycle of greater than 50% and less than 90%. Also provided is a means for shifting a phase of said counter-running guided modes within the cavity to alter a mode profile to increase a near field intensity of sai d output signal.