We report a high-power optically pumped semiconductor vertical external cavity surface emitting laser operating at 2-mum wavelength. The gain material consisted of 15 GaInSb quantum-wells placed within a three-lambda GaSb cavity and grown on the top of an 18-pairs AlAsSb/GaSb Bragg reflector. For thermal management we have used a transparent diamond heat spreader bonded on the top of the structure. When cooled down to 5 degrees C, the laser emitted up to 1 W of optical power in a nearly diffraction-limited Gaussian beam demonstrating the high potential of antimonide material for VECSEL fabrication.