Stimulated emission, gain, and coherent oscillations in II-VI semiconductor microcavities

The large oscillator strength for excitons in ZnSe-based quantum wells (QW's) is reflected in a normal-mode (Rabi) splitting which exceeds 10 meV per QW at low temperatures when measured by conventional linear optical probes or by four-wave mixing technique. The dominating impact of the electron-hole Coulomb interaction extends to high pair densities, including the regime of vertical cavity laser operation. Measurement of gain spectra shows how the composite photon-exciton oscillator supplies the optical gain for a laser operating beyond the perturbative regime.