Evaluation of Diffraction Orders Efficiency of Laguerre-Gaussian Beam Generated by the Phase and Amplitude Fork Grating Applied on Spatial Light Modulator

In this paper, Laguerre-Gaussian beams are produced by Computer Generated Hologram (CGH) on Spatial Light Modulator (SLM). The realization of CGH on SLM is simulated by the scalar diffraction theory. At first, Laguerre-Gaussian beam generation process is simulated by diffraction of laser light from phase and amplitude fork gratings in two types: blazed and binary grating and the results are compared. The higher efficiency is obtained for the blazed phase grating in the first order which is more important in our study. Recorded data from the experiment shows a good agreement with simulation results. In order to evaluate the topological charge of the generated Laguerre-Gaussian beam, the Mach-Zehnder interferometer setup is used.