Measuring enhanced optical correlations induced by transmission open channels in a slab geometry

Abstract

Owing to the existence of open channels, light could theoretically be transmitted through disordered media with 100% efficiency. However, because of the large number of channels to be controlled or measured, this has yet to be observed experimentally. To avoid this difficulty we consider observables that are easier to handle experimentally. By measuring the correlations of the field transmitted through a disordered medium, we were able to count the number of channels involved in transmission and to compare this number with theory. For a sample of transmission 1/25, we get a number of modes about 15 times smaller than for free space propagation. This figure is in good agreement with theoretical predictions.