Measuring laser beam parameters: phase and spatial coherence using the Wigner function

Detailed laser beam characterization is essential for the proper choice of lasers source according to the respective application as well as for the optimization of optical systems. Since most lasers generate partially coherent beams, intensity and phase distributions are not enough to describe them. In addition the knowledge of the coherence distribution is necessary. So far different setups have been used to measure phase and coherence distribution with limited accuracy. Here we demonstrate a new measurement procedure which is based on the retrieval of the Wigner distribution, from which all relevant information can be derived. The setup is very simple and the results seems to be fairly accurate.