High Power 1.5 μm Pulsed Semiconductor Laser Design with a Bulk Active Layer and an Asymmetric Waveguide

InGaAsP/InP high pulsed power lasers operating in the range of 1.3 - 1.6 mu m have been intensely studied recently, with LIDAR technology being the primary application. We present and analyse a design with a bulk active layer which has a large refractive index step with respect to the optical confinement layer and is located close to the p-cladding. It is shown that such lasers can allow a noticeable performance increase over the state of the art. The dependence of the laser performance on the design parameters including the thicknesses of the active layer and the waveguide, the cavity length, and the waveguide asymmetry, is analysed. It is shown that short cavity lengths (similar to 1 mm or even shorter) can be used in the design considered for achieving high pulsed power. Due to the significant waveguiding properties of the active layer, the use of both symmetric and asymmetric waveguide designs is possible, with only slightly higher output predicted for the asymmetric one. Both designs allow operation with a single, broad transverse mode enabling high brightness.