Abstract

Control of spontaneous emission in microcavities can significantly enhance the spontaneous emission coupling efficiency β, leading to high-efficiency and low-threshold lasers [1]. Enhanced β values of 0.01 ~ 0.05 have been demonstrated in a microdisk cavity [2] and in a hemispherical microcavity [3] by the incoherent optical pumping (high energy electron-hole pair excitation). If the pump wavelength is timed to the exciton resonance in the single quantum well (SQW) whose wavelength also matches with the resonance frequency of the microcavity, new coherent effect should appear such that coherently prepared excitonic dipole moments within the pumped area cooperatively emit coherent radiation which is enhanced by the high-Q microcavity. We report on the first observation of a spontaneous emission coupling efficiency approaching to unity (β ~ 1) by resonant excitation of the excitonic dipoles in the GaAs SQW inside the microcavity.

© 1993 Optical Society of America