PHOTON-NUMBER CORRELATIONS NEAR THE THRESHOLD OF MICROCAVITY LASERS IN THE WEAK-COUPLING REGIME

The quantum-noise properties near the threshold of microcavity lasers are studied theoretically and experimentally in the weak-coupling regi me. Computations based on two-level quantum theory show that the micro lasers exhibit a high degree of second-order coherence compared with c onventional lasers as a result of the suppression of spontaneous emiss ion into nonlasing modes, and that there always exists a finite thresh old for these lasers defined by the peak of the photon-number correlat ion function corresponding to the spontaneous-to-stimulated transition .