Complete spatial coherence characterization of quasi-random laser emission from dye doped transparent wood

We report on the experimental determination of the complete two coordinate spatial coherence function of light emitted by a quasi-random laser, implemented on recently introduced dye-doped transparent wood. The spatial coherence was measured by means of a double grating interferometer, which has some advantages over the standard Young's interferometer. Analysis of the spatial coherence reveals that emission from such a material can be considered as a superposition of several spatial modes produced by individual emitters within semi-ordered scattering medium. The overall degree of coherence, γ¯, for this quasi-random laser was found to be 0.16 ± 0.01, having possible applications in speckle free laser imaging and illumination.