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 mum. 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 3.4W at 10degC heatsink temperature. At 0degC, 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 M²~5 of was measured at maximum output power. Optimizing the beam quality of the laser resulted in a beam profile close to the Gaussian TEM₀₀ mode (M² ap 1.5) and still more than 2-W output power at 0degC.