Abstract

Inhibited spontaneous emission from excitons in semiconductors is an attractive phenomenon from the optical-device point of view.¹ In this paper we show that the spontaneous-emission power from the excitons in a quantum well can be reduced by embedding a thin quantum-well structure of high refractive index in a bulk material of low refractive index. In Fig. 1, we show such a quantum-well structure made up of a 50-Å GaAs quantum well sandwiched between two Al_xGa_1−xAs layers with a total thickness given by I_qw and a refractive index given by now. This quantum-well structure is shown embedded in a material with refractive index n = 1.5 and thickness I_B, We will show in this paper that the spontaneous-emission rate of the excitons in the quantum well can be reduced when 1_qw is thinner than λ/2. The thickness I_B has to be large compared to λ/2 so that the n = 1.5 regions will act like bulk materials.

© 1991 Optical Society of America