Experimental investigation of a multibeam holographic optical element matched to Gauss-Laguerre modes

An experimental investigation was made of the ‘modan’, a computer-generated holographic optical element which reconstructs the images of several modes. The modan was a matched spatial filter with angular separation of the channels. The results of measurements agreed with the theory and confirmed the expected performance of the modan. A comparison of two measurement methods led to recommendations on their use.