High-power high-brightness operation of a 2.25-mu m (AlGaIn)(AsSb)-based barrier-pumped vertical-external-cavity surface-emitting laser

We report on the output power performance and beam profile analysis of an optically pumped GaSb-based vertical-external-cavity surface-emitting laser operating at 2.25 mu m. The use of a SiC heatspreader and a precise control of the temperature-dependent modal gain allowed for improved high-power operation with a maximum continuous-wave output power of 3.4 W at -10 degrees C heatsink temperature. At 0 degrees C, a maximum output power >2.9 W was observed and still more than 1.6 W were obtained at room temperature. Using second-order moments for the definition of the beam diameter, a beam propagation factor of M-2 similar to 5 was measured at maximum output power. Optimizing the beam quality of the laser resulted in a beam profile close to the Gaussian TEM00 mode (M-2 approximate to 1.5) and still more than 2-W output power at 0 degrees C.