We report on the two-dimensional gap-soliton nature of exciton-polariton macroscopic coherent phases (PMCP) in a square lattice with a tunable amplitude. The resonantly excited PMCP forms close to the negative mass M point of the lattice band structure with energy within the lattice band gap and its wave function localized within a few lattice periods. The PMCPs are well described as gap solito...

Bose–Einstein condensates (BECs), the “fifth state of matter,” have in fact been discovered by chance both in liquid helium and in superconductors. Since these early encounters, BECs have been sought for, both in atom vapors and in solids. Here we report on the case of exciton polaritons. We discuss the experimental observation of macroscopically occupied polariton states and their possible att...

Using an angle-resolved heterodyne four-wave-mixing technique, we probe the low momentum excitation spectrum of a coherent polariton gas. The experimental results are well captured by the Bogoliubov transformation which describes the transition from single particle excitations of a normal fluid to soundlike excitations of a superfluid. In a dense coherent polariton gas, we find all the characte...

Use of large bandgap materials together with electrical injection makes the polariton laser an attractive low-power coherent light source for medical and biomedical applications or short distance plastic fiber communication at short wavelengths (violet and ultra-violet), where a conventional laser is difficult to realize. The dynamic properties of a polariton laser have not been investigated ex...

The experimental realization of Bose-Einstein condensation (BEC) with atoms and quasiparticles has triggered wide exploration of macroscopic quantum effects. Microcavity polaritons are of particular interest because quantum phenomena such as BEC and superfluidity can be observed at elevated temperatures. However, polariton lifetimes are typically too short to permit thermal equilibration. This ...

An ensemble of resonance atoms is considered, which are doped into a medium with well developed polariton effect, when in the spectrum of polariton states there is a band gap. If an atom with a resonance frequency inside the polariton gap is placed into the medium, the atomic spontaneous emission is suppressed. However, a system of resonance atoms inside the polariton gap can radiate when their...

We present evidence for the existence of a hybrid state of Tamm plasmons and microcavity exciton polaritons in a II-VI material based microcavity sample covered with an Ag metal layer. The bare cavity mode shows a characteristic anticrossing with the Tamm-plasmon mode, when microreflectivity measurements are performed for different detunings between the Tamm plasmon and the cavity mode. When th...

A massive redistribution of the polariton occupancy to two specific wave vectors, zero and approximately 3.9x10(4) cm(-1), is observed under conditions of continuous wave excitation of a semiconductor microcavity. The "condensation" of the polaritons to the two specific states arises from stimulated scattering at final state occupancies of order unity. The stimulation phenomena, arising due to ...

We report on the observation of optical Stark effects in J-aggregate-metal hybrid nanostructures exhibiting strong exciton-surface-plasmon-polariton coupling. For redshifted nonresonant excitation, pump-probe spectra show short-lived dispersive line shapes of the exciton-surface-plasmon-polariton coupled modes caused by a pump-induced Stark shift of the polariton resonances. For larger coupling...

The dynamics of propagating polariton condensates in one-dimensional microcavities is investigated through time resolved experiments. We find a strong increase in the condensate intensity when it travels through the nonresonantly excited area. This amplification is shown to come from bosonic stimulated relaxation of reservoir excitons into the polariton condensate, allowing for the repopulation...