Special Topic on Edge-Emitting Laser Simulation

Abstract: This topic uses Nuwa TCAD software to simulate the optoelectronic characteristics of FP, DFB, and BH DFB edge-emitting lasers. It showcases the modeling process for edge-emitting laser structures in Nuwa TCAD, including related model parameter settings and characteristic results. The goal is to enable users to fully understand and master the operation and usage of Nuwa TCAD software, allowing them to perform various simulations and optimization designs for edge-emitting lasers.

In recent years, VCSELs (Vertical Cavity Surface Emitting Lasers) have gained significant industry attention due to their structural advantages and have been applied in various fields. However, as the earliest type of semiconductor laser developed and used, Edge-Emitting Lasers (EEL), which emit lasers along the plane of the active layer, continue to play an essential role in optical communications, laser cutting, automotive lighting, healthcare, LiDAR, and emerging applications, with substantial development potential.

The transverse structure design of edge-emitting lasers determines the transverse modal characteristics of the device, such as beam shape, while the resonator design determines the longitudinal modal characteristics. The Fabry-Perot resonator forms the multi-longitudinal mode FP laser; distributed feedback grating structures form the single longitudinal mode DFB laser; distributed Bragg grating structures form the single longitudinal mode DBR laser; and periodic intersubband transitions in quantum wells create QCL (Quantum Cascade Lasers). The optoelectronic characteristics of edge-emitting lasers are influenced by their transverse structure and resonator design, along with factors like quantum well thickness, material composition distribution, doping distribution, ridge width, waveguide layer thickness, and grating structure and positioning, all of which affect carrier injection efficiency, SRH recombination, Auger recombination, differential gain, material gain, and longitudinal-transverse mode distribution. Thus, high-performance edge-emitting lasers require optimized structures and resonator designs, and device simulation is an economical and rapid method for performance optimization.

This special topic, based on device simulation technology, is specifically designed for edge-emitting lasers, focusing on the simulation and analysis process for FP, DFB, and BH DFB lasers, including structure construction, model settings, and result analysis, especially regarding different grating configuration methods. The objective is to enable users to understand and apply device simulation technology for performance optimization in edge-emitting lasers, ultimately supporting the enhancement and expansion of their applications.

2. Simulation Tools

For FP, DFB, and BH DFB edge-emitting lasers, this topic uses the Nuwa TCAD semiconductor process and device simulation software. Nuwa TCAD calculates the longitudinal and transverse modal characteristics of edge-emitting lasers using the effective refractive index method to solve the scalar optical wave equation, considers the coupling of optical, electrical, thermal, mechanical, tunneling, and self-heating models, and self-consistently solves the basic semiconductor drift-diffusion equations to simulate the optoelectronic characteristics of edge-emitting lasers.