Improving Blue InGaN Laser Diodes Performance with Waveguide Structure Engineering

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