Lasers Cooling Research On High Power VCSEL Arrays And The Fabrication Of VCSEL Arrays

One of the key problems is lasers cooling in researching high power VCSEL arrays. In order to increase the output power, stabilization and reliability, we considering the diffusion of heat generated by semiconductor lasers in the heat sink, the thermal interaction among single devices in the array have been analyzed. The idea of the thermal interaction caused from the diffusion of heat current is proposed. From analyses, we have got the theories that how to determine the separation between single devices in the array.A novel Ti/Ni/Au diamond metallization scheme applied in semiconductor lasers for thermal management is reported. The good adhesion strength between metal layers and diamond substrates is obtained using optimum pretreated, electron beam evaporation technique, and post-treatment processing. AES analysis shows that the Ni layer of diamond substrates to form TiC and TiO species on the interface during post-deposition annealing at 673K for 2h in vacuum. Further, RBS confirms that diamond(C)/Ti/Ni/Au is of good thermal stability at 673 K for lh in vacuum. Using a same semiconductor laser scheme, the thermal impedance of diamond thermal management is only 40% of A1N thermal management.For the Al_xGa_1-xAs/GaAs VCSEL fabrication, oxide-confined structure provide electrical and optical confinement. AlGaAs/GaAs VCSEL fabricated by selective oxidation and selective etching. The lowest threshold current 1.8mA is achieved with continuous-wave at room temperature, the maximum output power is 7.96mW.For the research work on the fabrication procedures, we discusses selective oxidation and selective wet etching. We found that the oxidation rate of AlxGa,_xAs layer is related to the AI concentration ,the thickness of Al_xGa_1-xAs layer ,the reaction temperature and the carrier gas flow. At last, we make sure the suitable condition of oxidation.