In-Well Pumped Membrane External-Cavity Surface Emitting Lasers (MECSELs) for Laser Guide Star Applications

Membrane external-cavity surface-emitting lasers (MECSELs) were first realized a decade ago [1], [2]. These vertically emitting semiconductor lasers offer significant potential and versatility for tailoring laser parameters. A key advantage of MECSELs is that they do not possess monolithically integrated semiconductor distributed Bragg reflectors (DBRs), which impede heat transfer and limit wavelength versatility due to strain and band gap engineering constraints. Additionally, the substrate on which the active region is grown is removed, leaving a thin active region membrane that is sandwiched between transparent intracavity heat spreaders to enhance thermal management [3]. Thanks to this membrane geometry, MECSELs inherently deliver excellent beam quality [2], [4], making them a highly advantageous type of semiconductor laser. As a result, MECSELs have seen rapid progress in recent years.