Improved spectral properties of an optically pumped semiconductor disk laser using a thin diamond heat spreader as an intracavity filter

This letter describes an optically pumped high-power InP-based semiconductor disk laser with a thin (50 μm) diamond heat spreader bonded to the surface of the gain chip. The diamond heat spreader performs the multiple functions of heat removal, spectral filtering, and wavelength stabilization by utilizing the high thermal conductivity and the low thermooptic coefficient of diamond, along with the large free-spectral range of a thin intracavity etalon. A pump-power-limited output power of 680 mW at 1.55 μm is demonstrated at a heat sink temperature of -30/spl deg/C, and 140 mW at room temperature. The spectral width was measured to be less than 0.08 nm and the spectral drift with temperature and pump power as low as 0.03 nm//spl deg/C and 0.14 nm/W, respectively.