A comprehensive beam propagation method (BPM) for the modeling of oxide-confined visible emitting (665nm) vertical-cavity surface-emitting lasers (VCSELs) aimed at polymer optical fibre (POF) communications is presented. In this model all the major physical processes, including the current density distribution, the self-heating effect of the devices, the carrier lateral diffusion in quantum wells, and the optical field modes are considered self-consistently. Using the model, the current flow, carrier diffusion in the active quantum wells, and temperature distribution are calculated. The model indicates severe current crowding around the edge of the oxide aperture within the VCSEL. Using a simple function to describe the variation of optical gain with temperature and wavelength, the threshold properties, transverse modes and the optical output current-light characteristics are calculated. The simulation results are compare favorably with measurements.