Ultrafast simulations of multimode VCSEL using optimized waist paraxial eigenmodes

An ultrafast two-dimensional (2-D) multimode vertical-cavity surface-emitting laser (VCSEL) simulation tool suite is introduced using eigenmode expansion of the rate equations, utilizing a novel generic representation for laterally open VCSEL cavity eigenmodes by optimized-waist paraxial modes. By avoiding the need to resolve short spatial and fast temporal scales, the code runs much faster than finite difference time domain and beam propogation method codes, retaining the 2-D description for the nonuniform carrier density and intensity profiles, multimode excitation, and axial carrier density depletion ("hole burning"). Code validation results against experimental measurements, such as steady-state NF mode structure, threshold gain versus aperture diameter, and dynamic mode switching, are presented. The code yields the correct behavior regarding aperture placement, with lower thresholds for aperture at node. Fast (<1 b/s) execution time allows detailed dynamic simulation of driven response over long input streams for the statistical extraction of bit-error rate and relative intensity noise figures of merit.