Efficient, high-power monolithic two-dimensional surface-emitting diode laser arrays mounted in the junction-down configuration

We review in-plane surface-emitting laser diode arrays and their applications. Efficient operation of monolithic, large area (0.54 cm 2 , 108 emitters) two-dimensional surface- emitting GaAlAs laser diode arrays mounted junction-down on microchannel heat exchangers has been demonstrated. Devices with 1.5 micrometers thick cladding layers were operated quasi- continuous-wave to high peak output power densities (> 100 W/cm 2 ), exhibited high power conversion efficiencies (22%), and full width emission spectra of 2 power density levels. This corresponded to a 550 W/cm 2 heat flux extracted by microchannel heat exchanges.