GaAs-based high temperature electrically pumped polariton laser

Abstract

Strong coupling effects and polariton lasing are observed at 155 K with an edge-emitting GaAs-based microcavity diode with a single Al0.31Ga0.69As/Al0.41Ga0.59As quantum well as the emitter. The threshold for polariton lasing is observed at 90 A/cm2, accompanied by a reduction of the emission linewidth to 0.85 meV and a blueshift of the emission wavelength by 0.89 meV. Polariton lasing is confirmed by the observation of a polariton population redistribution in momentum space and spatial coherence. Conventional photon lasing is recorded in the same device at higher pump powers.

Room temperature strong coupling in a semiconductor microcavity with embedded AlGaAs quantum wells designed for polariton lasing

“…Mixing of Γvalley electrons with the X-and L-valley leads to an increase of the electron effective mass which, in turn, should lead to an increase of the exciton binding energy that is proportional to its effective mass. Polariton lasing at 155 K was recently claimed for a sample with an Al0.31Ga0.69As/Al0.41Ga0.59As QW [25], but the unconventional microcavity geometry in a lateral configuration, which is highly unsuitable for advanced spectroscopic experiments, led to an open debate on the conclusions that were drawn based on measurements on such samples [26,27].…”

Resonant Bragg quantum wells in hybrid photonic crystals

“…Moreover, a multilayer system, where exciton energy is close to the transmission peak at high energy side of the stop band was studied experimentally by Askitopoulos et all. 11 as a new tools for tailoring of light-matter interaction, and promising for polariton lasing, which requires no population inversion 12,13 . At variance of microcavities, where the number of quantum wells are strongly limited, the RPBR, obtained by alternating isotropic materials with different background refraction indices and quantum well resonances, close to the Bragg frequency, require a number of elementary cells (N=30-60), greater than that present in the BDR microcavity, but no so large as those required in order to build up the former polaritonic gap 4,5 .…”

Small-signal modulation characteristics of a polariton laser

“…The device is commonly termed a polariton laser. Lack of the need for population inversion, as in a conventional laser, inherently enables coherent emission with thresholds that are generally 2–3 orders of magnitude lower than those measured for photon lasing in the same device 2 5 7 13 16 18 19 . The characterization of optically or electrically pumped polariton lasers made with a variety of material systems has enabled a detailed study of the underlying physical processes such as polariton scattering and Bose-Einstein condensation 20 21 22 23 , spontaneous symmetry breaking 24 and superfluidity 25 in the condensate.…”