Saturation of the strong-coupling regime in a semiconductor microcavity: Free-carrier bleaching of cavity polaritons

Houdré, R.; Gibernon, J. L.; Pellandini, P.; Stanley, R. P.; Oesterle, U.; Weisbuch, C.; O’Gorman, J.; Roycroft, B.; Ilegems, M.

doi:10.1103/physrevb.52.7810

Cited by 210 publications

(141 citation statements)

References 13 publications

Supporting

Mentioning

126

Contrasting

Unclassified

Order By: Relevance

“…Thus while the saturation nonlinearity discussed here is present for these excitations, it will be accompanied by other nonlinearities produced by the overlap of the wave functions of different excitons and the ionization of excitons. 34,35 These effects may well prevent condensation, but are separated from the saturation nonlinearity considered here in systems with localized, tightly bound excitons. Note also that tightly bound excitons have a large dipole coupling g, and hence the transition temperature will be large.…”

Section: Discussionmentioning

confidence: 99%

Bose condensation of cavity polaritons beyond the linear regime: The thermal equilibrium of a model microcavity

Eastham¹,

Littlewood²

2001

Phys. Rev. B

154

199

View full text Add to dashboard Cite

We consider a generalization of the Dicke model. This model describes localized, physically separated, saturable excitations, such as excitons bound on impurities, coupled to a single long-lived mode of an optical cavity. We consider the thermal equilibrium of this model at a fixed total number of excitons and photons. We find a phase in which both the cavity field and the excitonic polarization are coherent. This phase corresponds to a Bose condensate of cavity polaritons, generalized to allow for the fermionic internal structure of the excitons. It is separated from the normal state by an unusual reentrant phase boundary. We calculate the excitation energies of the model, and hence the optical absorption spectra of the cavity. In the condensed phase the absorption spectrum is gapped. The presence of this gap distinguishes the polariton condensate from the normal state and from a conventional laser, even when the inhomogeneous linewidth of the excitons is so large that there is no observable polariton splitting in the normal state.

show abstract

Section: Discussionmentioning

confidence: 99%

Bose condensation of cavity polaritons beyond the linear regime: The thermal equilibrium of a model microcavity

Eastham¹,

Littlewood²

2001

Phys. Rev. B

154

199

View full text Add to dashboard Cite

show abstract

“…The transition between weak-/strongcoupling in microcavities has been carefully studied. [2][3][4][5] This transition is governed by a condition on the exciton oscillator strength and decay rate, parameters that one can alter by changing the temperature, exciton density, or applying external fields. 6 Here we report clear evidence of the simultaneous presence of the perturbative ͑weak͒ and nonperturbative ͑strong͒ regimes when optically exciting semiconductor microcavities.…”

mentioning

confidence: 99%

Coexistence of low threshold lasing and strong coupling in microcavities

Lagoudakis

Martin

Baumberg

et al. 2004

Journal of Applied Physics

View full text Add to dashboard Cite

We report the coexistence of low threshold lasing and strong coupling in a high-quality semiconductor microcavity under near-resonant optical pumping. A sharp laser mode splits from the lower-polariton branch and approaches the bare cavity mode frequency as the pump power increases. The lasing is produced by low density localized exciton states, which are weakly coupled to the cavity mode. The appearance of this lasing mode distinguishes quantum-well excitons into those which are strongly or weakly coupled with the cavity mode. © 2004 American Institute of Physics. ͓DOI: 10.1063/1.1643191͔A photon mode in a Fabry-Perot resonator and an excitonic resonance in a semiconductor quantum well ͑QW͒ resemble two harmonic oscillators which can be either weakly or strongly coupled together in semiconductor microcavities containing embedded quantum wells. In the weak-coupling ͑WC͒ regime, resonant tuning of the cavity mode and the exciton transition results in formation of two degenerate states ͑a crossing behavior͒, while for strong-coupling ͑SC͒ on resonance, an energy splitting between new eigenstates of the system occurs ͑anticrossing situation͒.1 WC exists in vertical cavity surface emitting lasers ͑VCSELs͒ and leads to enhancement of the spontaneous emission of excitons in resonance with the cavity mode. The SC regime has also been intensively studied in the past decade as it offers a unique opportunity to observe optical effects associated with exciton polaritons, i.e., quasiparticles composed of half a photon and half an exciton, coherently propagating in the microcavity plane. The transition between weak-/strongcoupling in microcavities has been carefully studied.2-5 This transition is governed by a condition on the exciton oscillator strength and decay rate, parameters that one can alter by changing the temperature, exciton density, or applying external fields. 6 Here we report clear evidence of the simultaneous presence of the perturbative ͑weak͒ and nonperturbative ͑strong͒ regimes when optically exciting semiconductor microcavities. We observe an unambiguous anticrossing behavior of the coupled cavity and exciton modes, characteristic of the strong-coupling regime, while between these eigenstates of the system a new strong line appears whose intensity is exponentially dependent on the pumping power. An intermediate regime is identified where this lasing mode, which fulfills the characteristics of the weak-coupling regime, coexists with the free polariton modes. This extra mode results from the inversion of a population of localized exciton states. 7Population inversion at pump densities lower than the transition threshold density is possible in microcavities possessing a very low concentration of localized states. Thus a VC-SEL and strongly coupled exciton polaritons are simultaneously present in the same cavity.The semiconductor structure used in this study is a conventional cavity with optical linewidth ␥ c ϭ0.41 meV, and a single GaAs QW with exciton linewidth ␥ x ϭ0.44 meV, fully discussed in Ref. 8 ͑studi...

show abstract

“…However high carrier densities are required to trigger scattering stimulation but need to be small enough for phase space filling and screening to be negligible and exciton Bose commutator to be close to 1 [5]. The bleaching of the strong coupling regime is indicated by a broadening and a spectral shift of the polariton modes towards the uncoupled modes [6,7].…”

Section: Introductionmentioning

confidence: 99%

Stimulated Scattering of Microcavity Polaritons

et al. 2000

View full text Add to dashboard Cite

We report on cw optical experiments performed in a semiconductor microcavity containing a single quantum well in the strong coupling regime. Angularly resolved photoluminescence measurements under non-resonant excitation show the collapse of a relaxation bottleneck as the excitation power is increased. As a result, the emission close to kli = O presents a non-linear behavior. In a two-beam experiment we resonantly inject polaritons at ki = O and show that relaxation from states with large in-plane wave vector toward kll = O is stimulated by the polariton final state population.

show abstract

Saturation of the strong-coupling regime in a semiconductor microcavity: Free-carrier bleaching of cavity polaritons

Cited by 210 publications

References 13 publications

Bose condensation of cavity polaritons beyond the linear regime: The thermal equilibrium of a model microcavity

Bose condensation of cavity polaritons beyond the linear regime: The thermal equilibrium of a model microcavity

Coexistence of low threshold lasing and strong coupling in microcavities

Stimulated Scattering of Microcavity Polaritons

Contact Info

Product

Resources

About