Thermal Management of GaAs/AlGaAs VCSELs by Optimizing MHCG and DBR Hybrid Reflectors

In this paper, a self-consistent three-dimensional finite element method is used for the electro-thermal analysis of a VCSEL structure with a hybrid reflector based on monolithic high-contrast gratings (MHCG). A GaAs/AlGaAs VCSEL with a lasing wavelength of 980 nm, diameter of 31 µm and an aperture diameter of 16.5 µm with an MHCG and DBR hybrid reflector with reflectivity of 99.99% is studied, and the temperature distribution in the device is obtained. Also, the impact of utilizing MHCG in the reflector on the temperature peak is shown. The proposed structure is compared with a conventional VCSEL, and it is demonstrated that utilizing a hybrid reflector reduces the temperature peak by up to 8K. The effect of the MHCG duty cycle and thickness on VCSEL's electro-thermal characteristics is also investigated.