The theoretical diffraction efficiency upper limit of diffractive phase elements (DPE's) with finite apertures is investigated. A successful numerical method of evaluating the efficiency upper bound of DPE's is proposed. The method includes a hybrid optimization procedure that combines a genetic algorithm with the conjugate gradient method. This efficient global optimization technique can also be used to design DPE's. Simulation computations are detailed for rotationally symmetric beam shaping in which a Gaussian profile laser beam is converted into a uniform beam. Numerical results demonstrate that the estimated diffraction efficiency upper bound is consistent with the design results.
© 2000 Optical Society of America
Guangya Zhou, Xiaocong Yuan, Philip Dowd, Yee-Loy Lam, and Yuen-Chuen Chan, "Efficient method for evaluation of the diffraction efficiency upper bound of diffractive phase elements," Opt. Lett. 25, 1288-1290 (2000)