Dan Botez - Madison WI
Masoud J. Kasraian - Madison WI
Wisconsin Alumni Research Foundation - Madison WI
A high power monolithic surface emitting semiconductor laser provides a single lobe far-field radiation profile which is emitted normal to the plane of a surface of the semiconductor laser structure. The semiconductor laser includes an active region layer at which light is emitted and a complex-coupled distributed feedback grating positioned to act upon light from the active region. The adjacent elements of the distributed feedback grating differ from one another in both refractive index and gain/loss. The grating period, or the combined width of the two adjacent grating elements, is selected to be equal to a full wavelength in the semiconductor structure of the light emitted from the active region. Lasing occurs in a symmetric mode, resulting in emission of light from a planar surface of the semiconductor structure perpendicular to the surface, the grating layer and the active region layer as long as the modal-gain difference between symmetric and antisymmetric modes due to optical-field overlap with the gain/loss grating overcomes the modal-gain difference based on radiation losses.