Nonequilibrium condensates and lasers without inversion: Exciton-polariton lasers

A. Imamog¯lu, R. J. Ram, S. Pau, Y. Yamamoto

Research output: Contribution to journalArticlepeer-review

518 Scopus citations


We analyze elementary properties of exciton and polariton lasers — devices that generate coherent optical and matter waves using final-state stimulation of exciton-phonon scattering. First we discuss the relation between the conditions for the onset of equilibrium and nonequilibrium excitonic condensates. Provided that the thermal de Broglie wavelength [Formula Presented] exceeds the exciton Bohr radius [Formula Presented], an exciton laser operates without electronic population inversion. In contrast to previous proposals, this is a different type of laser without inversion which utilizes many-body coherences. When the excitonic character of the polariton branch vanishes, a polariton laser becomes indistinguishable from a photon laser.

Original languageEnglish (US)
Pages (from-to)4250-4253
Number of pages4
JournalPhysical Review A - Atomic, Molecular, and Optical Physics
Issue number6
StatePublished - 1996

ASJC Scopus subject areas

  • Atomic and Molecular Physics, and Optics


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