Measuring the azimuthal and radial indexes of laguerre-gaussian beams

A new pattern of mask for probing the azimuthal and radial indexes of Laguerre-Gaussian (LG) beams is presented. The analysis formula describing the intensity distribution of Laguerre-Gaussian beams after passing through the mask is derived. Based on this formula, the intensity patterns for different azimuthal and radial indexes are obtained via numerical simulations. It's indicated that for each pair of azimuthal and radial indexes, there is a defined intensity pattern in the observed plane, according to which the azimuthal and radial indexes can be measured. Using this method, the communication systems with large capacity can be achieved, which are encoded by the azimuthal and radial indexes of Laguerre-Gaussian beams simultaneously. © 2010 Tianjin University of Technology and Springer-Verlag Berlin Heidelberg.