Analysis of a dual grating-type surface emitting laser

The grating-coupled surface emitter (GSE) consists of a gain section between two grating sections, which are not necessarily identical. The gratings act as both distributed Bragg reflectors and output couplers. An analysis that applies to arbitrary grating shapes and has provisions to include the presence of a substrate reflector to reduce the radiated power into that medium is carried out. Thresholds, differential efficiencies, and far-field patterns are compared for the low-threshold longitudinal modes of the system. Examples illustrating variations in tooth shapes and heights, waveguide loss, the presence of a substrate reflector, and detuning from the Bragg condition are included.