Evaluation of heat dissipation characteristics of quantum cascade laser with diamond submount using structure function and three-dimensional thermal fluid simulation

Abstract

The heat dissipation of a quantum cascade laser (QCL) for a mounted structure with and without a diamond submount was evaluated by temperature and structure function measurements and three-dimensional simulation. From the structure function, it was shown that the thermal resistance between the QCL on the InP substrate and the CuW mount was reduced from 5.0 K W−1 without the submount to 2.5 K W−1 with the diamond submount. In the 3D simulation, it was confirmed that the heat flux transmitted horizontally through the diamond mount is larger than that without the submount. It is considered that the heat flux in the horizontal direction improved the heat dissipation from the InP substrate to the CuW mount. As a result, the output of the QCL with the submount was 1.15 times that of the QCL without the submount.