Transverse laser-mode structure determination from spatial coherence measurements: Experimental results

We demonstrate experimentally the feasibility of a certain coherence-theoretic algorithm for determining the relative modal weights of a laser beam that consists of multiple Hermite-Gaussian transverse modes. A computer-controlled Young's two-pinhole interferometer with a linear CCD array is used for the coherence measurements. The required scaling parameter (beam width) is obtained iteratively by library routines. Numerical simulations on the stability of the algorithm in the presence of experimental noise are also presented.