TIME-RESOLVED OBSERVATION AND MEASUREMENT OF MULTIPLE-WAVELENGTH LASER-EMISSION IN MULTIPLE-QUANTUM-WELL VERTICAL-CAVITY STRUCTURES

Pulsed optical pumping experiments have been performed at room tempera ture on vertical-cavity multiple-quantum-well structures with picoseco nd light sources. Lasing is found to occur at various wavelengths corr esponding to the longitudinal modes of the Fabry-Perot cavity. Time-re solved study of laser emission is crucial close to threshold, since it can discriminate between real laser emission and under-threshold lumi nescence. Because of the different net gains for the modes and because of nonlinear gain, the different lines are emitted successively under specific pumping conditions; this phenomenon could affect the operati on of recently proposed multiple-wavelength vertical-cavity lasers.