An analytic expression of enhanced spontaneous emission in semiconductor microcavity lasers

Based on the enhanced spontaneous emission caused by microcavity and influence of nonradiative recombination, an analytic resolution of rate equation is derived for microcavity lasers. It is evident that such high spontaneous emission factor value can be used to enhance the efficiency of light-emitting and lower thresholds of lasers. The Light output is increased by the enhanced well number and by the decreased width, at the same time the sharpness of those variation depends on spontaneous emission factor. We show that the characteristic curve of a " thresholdless" laser is strongly nonradiative depopulation-dependent. When nonradiative depopulation is no zero even for an ideal closed microcavity, the light-current characteristic is not Linearly. The result shows that increasing the coupling of spontaneous emission into the cavity mode causes the lasing properties becoming quite different from those of the conventional laser having cavity dimensions much larger than the lasing wavelength.