Statistical properties of speckle distributions in resonant secondary emission

Quantitative analysis of speckle distributions, i.e., intensity fluctuations, in resonant secondary emission is a powerful tool to study quantum coherence in a wide range of optically excited systems. Finite directional or temporal resolution and any instability in the setup will necessarily reduce the fluctuations which would be misinterpreted as loss of coherence. We discuss the consequences of this averaging and show how the amount of averaging can be extracted from histograms of the speckle intensity and how it can be corrected for. Using functional integration methods, analytic expressions for the intensity distribution in experiments with finite directional or temporal resolution are derived. These should help to make the quantitative speckle analysis a widely used technique for measuring quantum coherence optically.