Coherence properties of exciton polariton OPO condensates in one and two dimensions

R Spano,J M Hvam,M D Martín,M Van Der Poel,L Viña,C A Lingg,J Cuadra,C Antón,P R Eastham,D Sanvitto,G Tosi

doi:10.1088/1367-2630/14/7/075018

R Spano, J M Hvam + Show 9 more

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https://doi.org/10.1088/1367-2630/14/7/075018

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Abstract

We give an overview of the coherence properties of exciton–polariton condensates generated by optical parametric scattering. Different aspects of the first-order coherence (g(1)) have been investigated. The spatial coherence extension of a two-dimensional (2D) polariton system, below and at the parametric threshold, demonstrates the development of a constant phase coherence over the entire condensate, once the condensate phase transition takes place. The effect on coherence of the photonic versus excitonic nature of the condensates is also examined. The coherence of a quasi-1D trap, composed of a line defect, is studied, showing the detrimental effect of reduced dimensionality on the establishment of the long range order. In addition, the temporal coherence decay, , reveals a fast decay in contrast with the 2D case. The situation of a quasi-1D condensate coexisting with a 2D one is also presented.

Highlights

We give an overview of the coherence properties of exciton–polariton condensates generated by optical parametric scattering
The pioneering work of Baas et al [19] shows for the first time that a very extended spatial coherence can be achieved in an OPO condensate
In the case of an ideal disorder-less scenario, they predict that the spatial coherence along the 1D condensate direction (y) decays with an exponential law: g(1) (y) ∝ e−|y|/lc, with lc being the coherence length, which they estimate to be of the order of a few hundreds of microns

Summary

Introduction

We give an overview of the coherence properties of exciton–polariton condensates generated by optical parametric scattering. They present a preliminary study of the coherence properties of a 1D OPO system, where the coherence is expected to decay rapidly along the condensate length even when pumping at the parametric threshold, ETh. For atomic condensates, which are equilibrium systems, the theory developed in [17] for the 1D case predicts an exponential decay of the phase coherence.

Results

Conclusion