Generation of uniform-intensity light beams with controllable spatial shapes

Abstract

We present the generation of high-quality light beams of controllable spatial shapes with uniform-intensity distribution based on diffractive optical elements (DOEs) designed by an iterative method that involves spatial Fourier filtering. The Gaussian input beam illuminates the DOEs, and after propagating certain distance transforms into desired uniform-intensity output beams with square, annular, rectangular, hollow square, and plus spatial shapes. We have performed a detailed robustness analysis on the quality of shaped output beams against various types of imperfections in an input beam. It is found that the quality of shaped output beams can be further improved by using additional spatial filtering. Furthermore, we have shown that the quality of shaped output beams remains excellent even when DOE (designed for a specific wavelength) is illuminated by input beam with different wavelengths over a broad range.