Temperature dependence of the spontaneous emission factor in VCSELs

The spontaneous emission factor β is studied as a function of temperature using k-, no k- and partial k-selection for bulk and multiquantum-well vertical-cavity surface-emitting lasers (VCSELs). This gives an improved insight into the behaviour of spontaneous emission as a function of temperature in such lasers where the resonant wavelength is chosen by the cavity and does not necessarily follow the peak gain. The calculated temperature dependence of the spontaneous emission factor exhibits a broad maximum associated with the alignment of the peak gain and cavity resonance. Spectral broadening effects affect this temperature dependence for the partial k-selection case at low temperatures where the cavity resonance lies within the low-energy spectral tail