NONLINEAR LEAST-SQUARES AND PHASE-SHIFTING QUANTIZATION METHODS FOR DIFFRACTIVE OPTICAL-ELEMENT DESIGN

A new, to our knowledge, design method for diffractive optical element s (DOE's) is described and compared with existing methods. The techniq ue applies a nonlinear least-squares algorithm to design two-dimension al pure phase DOE's that reconstruct a desired diffraction pattern wit h high uniformity, efficiency, and signal-to-noise ratio. The techniqu e also uses a phase-shifting quantization procedure that greatly reduc es the quantization error for DOE's to a minimum level. In this paper, we compare simulated reconstruction results of DOE's designed by use of these methods with results obtained by the commonly used two-stage iterative Fourier transform design algorithm of Wyrowski. (C) 1997 Opt ical Society of America.