Cavity polaritons, the elementary optical excitations of semiconductor microcavities, may be understood as a superposition of excitons and cavity photons(1). Owing to their composite nature, these bosonic particles have a distinct optical response, at the same time very fast and highly nonlinear. Very efficient light amplification due to polariton-polariton parametric scattering has recently been reported in semiconductor microcavities at liquid-helium temperatures(2-11). Here we demonstrate polariton parametric amplification up to 120 K in GaAlAs-based microcavities and up to 220 K in CdTe-based microcavities. We show that the cut-off temperature for the amplification is ultimately determined by the binding energy of the exciton. A 5-mum-thick planar microcavity can amplify a weak light pulse more than 5,000 times. The effective gain coefficient of an equivalent homogeneous medium would be 10(7) cm(-1). The subpicosecond duration and high efficiency of the amplification could be exploited for high-repetition all-optical microscopic switches and amplifiers. 10(5) polaritons occupy the same quantum state during the amplification, realizing a dynamical condensate of strongly interacting bosons which can be studied at high temperature.
WOS:000172676200042
2001
414
6865
731
735
Swiss Fed Inst Technol Lausanne, PH Ecublens, Dept Phys, CH-1015 Lausanne EPFL, Switzerland. CNRS, L2M, F-92225 Bagneux, France. Univ Grenoble 1, Spectrometrie Phys Lab, F-38402 St Martin Dheres, France. Univ Cagliari, Dipartimento Fis, I-09042 Monserrato, Italy. Univ Cagliari, Ist Nazl Fis Mat, I-09042 Monserrato, Italy. Saba, M, Swiss Fed Inst Technol Lausanne, PH Ecublens, Dept Phys, CH-1015 Lausanne EPFL, Switzerland.
ISI Document Delivery No.: 501GD
Cited Reference Count: 20
Cited References:
BAUMBERG JJ, 2000, PHYS REV B, V62, P16247
BLOCH J, 1998, APPL PHYS LETT, V73, P1694
CIUTI C, 2000, PHYS REV B, V62
CIUTI C, 2001, PHYS REV B, V63
DANG LS, 1998, PHYS REV LETT, V81, P3920
DASBACH G, 2000, PHYS REV B, V62, P13076
EHRENSTEIN D, 2000, PHYS REV FOCUS, V5
HOUDRE R, 2000, PHYS REV LETT, V85, P2793
HUANG R, 2000, PHYS REV B, V61
IMAMOGLU A, 1996, PHYS REV A, V53, P4250
KELKAR PV, 1997, PHYS REV B, V56, P7564
LIDZEY DG, 1998, NATURE, V395, P53
LIDZEY DG, 2000, SCIENCE, V288, P1620
PEARTON SJ, 1999, J APPL PHYS, V86, P1
PONCE FA, 1997, NATURE, V386, P351
SAVVIDIS PG, 2000, PHYS REV B, V62, P13278
SAVVIDIS PG, 2000, PHYS REV LETT, V84, P1547
STEVENSON RM, 2000, PHYS REV LETT, V85, P3680
WEISBUCH C, 1992, PHYS REV LETT, V69, P3314
YAMAMOTO Y, 2000, NATURE, V405, P629
REVIEWED
EPFL