Abstract

We report here the first investigation of femtosecond time-resolved emission from a semiconductor microcavity resonantly excited with intense femtosecond pulses. The emission intensity, which exhibits a strong threshold behavior, shows novel, well-pronounced oscillations that have a period of 600 fs and that last for several picoseconds. These THz oscillations can be associated with the appearance of a new mode in the spectrum and become more pronounced with pump intensify. The frequency of these oscillations is 20 times higher than those reported previously [1]. Our investigation probes novel aspects of semiconductor microcavities and vertical-cavity surface-emitting lasers that have attracted considerable interest recently [1-6]. Observations reported earlier include: coherent vacuum Rabi oscillations after weak resonant optical excitation [2-4], the emission of single pulses after nonresonant optical pumping [5], and relaxation oscillations after electrical pumping [1].

© 1996 Optical Society of America