Optimized Design and Numerical Modeling of 850 nm Vertical-Cavity Surface-Emitting Laser (VCSEL)

850µm-wavelength 1D Vertical Cavity Surface Emitting Laser (VCSELs have matured as a short-distance optical communication light source that has small threshold currents, high modulation band width, and multimode fibers. In this paper, the design, simulation and analysis of an 850 nm oxide-confined 1DVCSEL have been presented using the Laser MOD tool from R-Soft software. The structure is a cylindrical-shaped design consisting of top and bottom DBRs, a multi-quantum well (MQW) active region, and an oxide aperture for transverse current for optical confinement. The numerical investigation gives rise to the spatial mode profiles, modal gain, threshold current, output power and far-field angle in terms of cavity or oxide aperture length, as well as amount of doping. For optimized performance, the cavity length was optimized to be 8.6 µm and the oxide aperture diameter 10 µm, resulting in single fundamental mode operation with high side-mode suppression. The far-field pattern is nearly Gaussian in shape and well suited for efficient coupling into multi-mode fibers. This work highlights the potential of Laser MOD for predictive design and optimization of VCSEL devices designed for high-speed data communication.