High average output power from a backside-cooled 2-µm InGaSb VECSEL with full gain characterization

Abstract

We report record performance and full gain characterization of an optically pumped continuous wave InGaSb VECSEL operating around 2 µm. Our flip-chip processed and backside-cooled VECSEL performs similar to intracavity heatspreader cooling and obtained even similar thermal resistance of only 3.45 KW-1 and an average output power of >800 mW. Our gain characterization setups can cover a wavelength range from 1.9 µm to 3 µm. Linear and nonlinear gain characteristics are measured as a function of wavelength, fluence, pump power and heatsink temperature. 2-µm VECSEL chips with different strategies in heat management are compared and theoretical predictions are in good agreement.