Optimization of semiconductor ridge waveguide lasers for improved temperature characteristics

Summary form only given. Semiconductor ridge waveguide (RWG) laser fabrication process has been optimized. RWG lasers with different ridge height of 0.39 μm, 0.80 μm, 1.23 μm, 1.55 μm and 1.77 μm were fabricated. All the RWG lasers have the same contact ridge width of 50 μm and cavity length of 1100 μm. The dependence of the ridge height on the temperature performance of these lasers has been systematically investigated. It was found that the optimum ridge height is 1.23 μm, corresponding to an etching depth where all the p-doped layers above the active region were removed. The RWG laser with this ridge height worked up to 100 °C successfully, and also showed the highest characteristic temperature (T
₀
) among all the five group lasers. The T
₀
became worse when the ridge height extends below the active region. Our study suggests the significance of the optimization of the ridge waveguide to the laser diode performance.