Improving the Thermal Characteristics of Semiconductor Lasers Using a New Asymmetric Waveguide Structure

Self-heating leads to a temperature rise of the laser diode and limits the output power and efficiency due to increased loss and decreased differential gain. To control device self-heating, it is required to design the laser structure with a low optical loss, while the heat flux must spread out of the device efficiently. In this study, a new asymmetric waveguide design is proposed and the thermal performance of the laser with this new design is theoretically analyzed and compared with conventional symmetric waveguide laser. For this purpose, the simulation PICS3D software is used, which self-consistently combines 3D simulation of carrier transport, self-heating, and optical wave-guiding. According to the numerical simulation results, when the asymmetric waveguide is used the semiconductor laser shows a higher output light power and slope efficiency. The results show that Joule heating decreases and recombination heat increases, but heat dissipation occurs more effectively due to increased cooling densities. Overall, the maximum laser operation temperature decreases, confirming that our new asymmetric waveguide structure improves laser thermal characteristics.