High Occupancy Effects and Condensation Phenomena in Semiconductor Microcavities and Bulk Semiconductors

Abstract

Semiconductor microcavities are micron scale photonic structures in which quantum wells are embedded within a high finesse Fabry-Perot cavity, the whole structure being prepared by high precision, modern crystal growth techniques [1]. In such structures vertical confinement of both excitons in the quantum wells and of light within the Fabry-Perot cavity results in strong and controllable light-matter interactions unachievable in quantum wells or bulk semiconductors. This control has opened up a new field of exciton-polariton physics, where key features of the interacting exciton-photon system can be tailored by sample design. Most importantly for the physics described here, the dispersion curves of the coupled two-dimensional (2D) exciton-photon modes, exciton-polaritons (termed cavity polaritons), differ from those of their bulk analogues since the confinement of light results in a finite energy at k=0. This property, combined with the controllable dispersion and the extremely low density of polariton states [1], has recently allowed a variety of new phenomena to be observed, including final state stimulation and a new condensed phase with macroscopic coherence, which have the potential to lead to new devices including very low threshold optical parametric oscillators and a coherent light source based on stimulated polariton scattering.KeywordsOptical Parametric OscillatorResonant ExcitationAmerican Physical SocietyBulk SemiconductorCondensation PhenomenonThese keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.