Effect of Non-Resonant Gain Structure Design in Membrane External-Cavity Surface-Emitting Lasers

Abstract

The operation of a semiconductor membrane external-cavity surface-emitting laser (MECSEL) employing a gain membrane with a cavity design, which is non-resonant regarding the two semiconductor -heat-spreader interfaces, is presented. The MECSEL delivers watt-level output power, in line with state-of-the-art results. The study provides new evidence that the design criteria of a MECSEL gain region are significantly relaxed compared to active regions employing distributed Bragg reflectors, for which the field distribution is set by the Bragg condition leading to tight tolerances for positioning of the emitting quantum structures. The study has relevance especially for the development of mode-locked MECSELs by minimizing the impact of defective Fabry-Pérot micro-cavity effects due to reflections between the semiconductor gain structure and the two heat-spreader elements placed on each side of the semiconductor membrane.

2-μm 1.5-W Optically Pumped Semiconductor Membrane Laser

“…Further confinement, preventing carrier runaway, is achieved using AlAs 0.08 Sb 0.92 as cladding material. The design incorporates antiresonant closings on both sides, contributing to the stability and performance of the MECSEL [20]. The Molecular Beam Epitaxy (MBE) growth on an GaSb wafer was started with a 150-nm InAs 0.91 Sb 0.09 layer which forms an etch stop for subsequent wafer removal.…”