16 W DBR-free semiconductor disk laser using dual-SiC-heatspreader (Conference Presentation)

Abstract

With ultrathin gain media, traditional vertical-external-cavity surface-emitting lasers (VECSELs) in theory allow for ideal power scaling with mode area given the one-dimensional heat flow from the active material and into the underlying heatsinking structure. In experiments, however, the integrated semiconductor distributed Bragg reflector (DBR) and its large thermal resistance hamper that scalability. DBR-free semiconductor disk lasers (SDLs), using gain membranes without DBRs and taking advantage of direct bonding, allow for heat dissipation from both sides of the gain medium. Our previous numerical thermal analysis has shown potential advantages in thermal management for this dual-heatspreader configuration, or membrane external-cavity surface-emitting laser (MECSEL) structure, over traditional VECSELs. In this paper, we present both theoretical and experimental performance comparisons between DBR-free SDLs in both single- and dual-heatspreader configurations. Under similar cavity and pumping conditions, the dual-heatspreader configuration has a comparable slope efficiency but experiences thermal roll-over at twice the incident pump power when compared to the single-heatspreader configuration. After optimization of the output coupling efficiency, a maximum output power of 16 W near 1040 nm is collected with the dual-SiC-heatspreader configuration at a coolant temperature of 10 C. With the availability of wafer-scale SiC heatspreaders, we show the potential for mass production of SDLs employing a dual-heatspreader configuration.