Investigation of thermal management in optically pumped, antimonide VECSELs

In this work, an optical modulation spectroscopy technique: thermoreflectance has been employed to study temperature distributions on the surface of optically pumped vertical external cavity surface emitting lasers (VECSELs). The thermoreflectance is based on the relative change of reflectivity of the sample induced by the change of its temperature. In this case the temperature change of the sample is induced by operating the pump in pulse mode. We have investigated samples with and without intracavity heatspreader. The resulting temperatures and temperature distributions on the sample surface have been measured and compared with theoretical calculations. The results confirm the effectiveness of silicon carbide (SiC) heatspreader approach. This is also a first report on the direct temperature mapping on VECSELs, with micron spatial resolution.