DESIGN OF FAN-OUT KINOFORMS IN THE ENTIRE SCALAR DIFFRACTION REGIME WITH AN OPTIMAL-ROTATION-ANGLE METHOD

An algorithm for the design of diffractive optical phase elements (kin oforms) that give rise to fan-out (i.e., spot) patterns was developed and tested. The algorithm is based on the Helmholtz-Kirchhoff rigorous scalar diffraction integral for the evaluation of the electric field behind the kinoform. The optimization of the kinoform phase modulation is performed with an efficient optimal-rotation-angle method. The alg orithm permits any spatial configuration of the locations of the desir ed spots. For example, the spots (all or some) can be located at large angles to the optical axis (nonparaxial case) or they can be located in the near near field of the kinoform, i.e., where the Fresnel approx imation is no longer valid. Two examples of fabricated kinoforms desig ned with this algorithm are presented. (C) 1997 Optical Society of Ame rica.