Transverse optical mode analysis of long-wavelength VCSELs for high single-mode power operation

We present a detailed numerical study of transverse mode selection of vertical-cavity surface-emitting lasers (VCSELs), based on microscopic models of charge carrier and temperature distributions solved self-consistently together with the optical modes. The simulations describe several measured device characteristics of tunnel junction double-fused VCSELs, in particular the switching between the fundamental and the excited transverse modes. As a conclusion, the onset of the multi-mode regime is shown to result from a combination of thermal lensing and gain-guiding mechanisms as well as spatial hole burning.