Improving Blue InGaN Laser Diodes Performance with Waveguide Structure Engineering

To enhance lasers’ power and improve their performance, a model was applied for the waveguide design of 400 nm InGaN/InGaN semiconductor laser, which is much easier to implement. The conventional and new laser structures were theoretically investigated using simulation software PICS3D, which self-consistently combines 3D simulation of carrier transport, self-heating, and optical waveguiding. Excellent agreement between simulation and experimental results was obtained by careful adjustment of the material parameter in the physical model. Numerical simulation results demonstrate that the new waveguide structure can efficiently increase the output power, lower the threshold current, and improve the slope efficiency, which is simply applicable to any kind of InGaN edge emitting lasers. Flatten band gap in the p-side of the InGaN laser diode in new laser structure resulted in an increase in the hole current density in the quantum well while simultaneously the electron confinement in the active region was effectively created, leading to the increased stimulated recombination rate. Furthermore, optical mode-overlap with heavily p-doped was declined, which is the main reason for a better performance of InGaN laser diode.