GUERIN , W

Cooperative scattering has been the subject of intense research in the last years. In this article, we discuss the concept of cooperative scattering from a broad perspective. We briefly review the various collective effects that occur when light interacts with an ensemble of atoms. We show that some effects that have been recently discussed in...

We present a preliminary laboratory test of a setup designed to measure Hanbury Brown and Twiss-type intensity correlations from a chaotic light source using five spectral channels simultaneously. After averaging the zero-delay correlation peaks from all channels, we obtain an improvement of the signalto-noise ratio fairly consistent with...

We study the crossover between the diffusive and quasi-ballistic regimes of random lasers. In particular, we compare incoherent models based on the diffusion equation and the radiative transfer equation (RTE), which neglect all wave effects, with a coherent wave model for the random laser threshold. We show that both the incoherent and the...

We present temporal intensity correlation measurements of light scattered by a hot atomic vapor. Clear evidence of photon bunching is shown at very short timescales (nanoseconds) imposed by the Doppler broadening of the hot vapor. Moreover, we demonstrate that relevant information about the scattering process, such as the ratio of single to...

We report the first intensity correlation measured with star light since Hanbury Brown and Twiss' historical experiments. The photon bunching g (2) (τ, r = 0), obtained in the photon counting regime, was measured for 3 bright stars, α Boo, α CMi, and β Gem. The light was collected at the focal plane of a 1 m optical telescope, was transported...

Intensity Interferometry offers an interesting path forward for astronomical interferometry at very long baselines and at short wavelengths, all leading to extremely high angular resolution. Single photon counting detectors (and associated correlator technology) has evolved to allow a sensitivity gain of two orders of magnitude since the...