Spontaneous-emission-lifetime alteration in ${\mathrm{In}}_x{\mathrm{Ga}}_{1-x}\mathrm{As}$/GaAs vertical-cavity surface-emitting laser structures

The spontaneous-emission lifetime of ${\mathrm{In}}_{0.2}{\mathrm{Ga}}_{0.8}\mathrm{As}$/GaAs vertical-cavity surface-emitting laser structures was investigated at room temperature as a function of reflectivity of AlAs/GaAs distributed Bragg reflectors (DBR’s). As the reflectivity of DBR’s became higher, the spontaneous-emission lifetime measured at the resonance wavelength of the cavity became drastically shorter in the cavity axis direction. This spontaneous-emission-lifetime alteration was much more than that of the previous experimental results for quantum wells and the theoretical estimation for atomic dipoles in the planar microcavity structures.