Fabrication Process For High Efficiency And High Power Semiconductor Lasers

High power semiconductor lasers have great potential in the application of pumping solid state laser, industrial processing, medical treatment, information storage and military equipment due to its superior characteristics such as high electrical-to-optical conversion efficiency (about 40%), stable operation, compactness and simple electrical driving ability. In the last few years there have been great advances in the improvement and the application of high power semiconductor lasers abroad, but the output power of semiconductor lasers has not been got great improvement in our country within quite a long time. Development of high power semiconductor lasers have faced serious problems in heat-dissipation, catastrophic optical damage(COD) near the lighting-emitting surface of cavity and joule heat damage produced when laser diode(LD) is working under an high driving current. So in this thesis for the main problems of high power semiconductor lasers , we hope to find steps to decrease threshold current, enhance the quantum efficiency and electrical-to-optical conversion efficiency, prolong the device life and improve the device reliability .Main device processes (ohmic contact,surface passivation,facet coating,packaging and so on) have been explored and the device characterization has been discussed. The main work is summarized as the follows:1. The main fabrication problems with high power semiconductor lasers are analyzed.2. Basing on the device theory, principal design has been given to improve LD's efficiency and output power.3. The optimization for the layer structure and process condition has been explored, The minimum contact resistivity is as low as 0.12O and the power conversion efficiency has been improved for a low joule heat generation.4. The facet mirror coating has been done for conversion efficiency optimization of the prepared devices.5. The LD packaging problem has been analyzed.