Analysis of transverse mode competition of VCSELs based on a spatially independent model

A spatially independent model of vertical-cavity surface-emitting lasers (VCSELs) is built up in this paper by integrating the spatially dependent rate equations over the cross section of the active region of a VCSEL. The transverse modal structure is presented and discussed. This model is simulated numerically with the fourth-order Runge-Kutta method in a self-consistent way. Different kinds of injection currents such as a disk-contact and a ring-contact of injection current with different current parameters are employed in the investigations. The dependencies of the transverse mode competition on the current intensity, the current spread, and the geometrical parameters of the injection contact forms are thoroughly investigated and analyzed. The results are useful to design and control the transverse modal profile of a VCSEL.