Optical switching of polariton density patterns in a semiconductor microcavity

Abstract

Phase-conjugate scattering can trigger modulational instabilities in a fluid of exciton-polaritons created in a pumped semiconductor quantum-well microcavity. These instabilities can settle into density patterns, e.g. hexagons and stripes, which produce corresponding patterns in the emitted light. The density patterns can be switched by relatively weak control optical beams. This paper reviews progress in our theoretical understanding of the physical processes that regulate the competitions among various patterns and drive the optical switching. Simulation results of pattern switching using a microscopic model of polariton dynamics are shown, and the mechanisms underlying competitions and switching are analyzed using reduced models that restrict the polariton motions to a limited number of relevant modes. We also briefly indicate the effects of the spin dependence of the polariton dynamics on the patterns.

Spontaneous patterns in coherently driven polariton microcavities

“…This contrasts with the case of single-pump instabilities, for which parametric scattering occurs at the same energy as one of the two pumps. In this case, it was already shown that hexagonal patterns are the most common instabilities [9][10][11][12][13]. We demonstrate that our set up allows two-pump instabilities to compete against single-pump instabilities, and that the system can simultaneously undergo different instabilities at different energies.…”

“…1. This contrasts with the single-pump case, where, because of cubic order processes, hexagonal patterns are the most common instabilities [9][10][11][12][13].…”

“…This was predicted by Refs. [9][10][11][12] and experimentally realised in [13] using a double vertical cavity. Alternative patterns such as vortices and vortex lattices [14][15][16], vortex rings [17], and solitons [18] have also been investigated in polariton quantum fluids driven by a resonant pump.…”

All-optical beam steering using the polariton lighthouse effect

“…The physical processes giving rise to the 180 • (2-spot) and 60 • angles (6-spot) are illustrated in Ref. 27 For a conventional single-cavity design, we have also found the possibility of 90 • angles 28 (4-spot) in the case of linearly polarized pump beams. These 90 • angles patterns are made possible by the interplay between the exciton-exciton interaction and TE-TM splitting.…”

Critical dynamics and tree-like spatiotemporal patterns in exciton-polariton condensates

“…Spatial pattern formation in polariton systems has been studied in a number of different configurations both theoretically and experimentally [19][20][21][22][23][24][25][26][27][28][29][30][31][32][33] . In this work, we investigate dynamical behavior close to the instability threshold in detail, and predict spatiotemporal pattern formation.…”