Temperature dependence of the spontaneous emission factor in VCSELs

The spontaneous emission factor beta is studied as a function of temperatur e using k-, no k- and partial k-selection for bulk and multiquantum-well ve rtical-cavity surface-emitting lasers (VCSELs). This gives an improved insi ght into the behaviour of spontaneous emission as a function of temperature in such lasers where the resonant wavelength is chosen by the cavity and d oes not necessarily follow the peak gain. The calculated temperature depend ence of the spontaneous emission factor exhibits a broad maximum associated with the alignment of the peak gain and cavity resonance. Spectral broaden ing effects affect this temperature dependence for the partial k-selection case at low temperatures where the cavity resonance lies within the low-ene rgy spectral tail.