Phase function encoding of diffractive structures

We analyzed the direct sampling (DS) method for diffractive lens encoding, using exact electromagnetic diffraction theory. In addition to previously p ublished research [Pure Appl. Opt. 7, 565 (1998)] we present what we believ e to be new results for TM polarization. We found that the validity of the scalar-based DS method is even more extended for TM than for TE polarizatio n. Additionally, we fabricated and characterized DS-encoded blazed gratings and found good agreement between the experimental and theoretical diffract ion efficiencies. We analyzed quantitatively the influence of the encoding schemes DS and analytic quantization (AQ) on the quality of the focal spot. We also investigated the focal spot sizes (FWHM) and the Strehl ratios of the DS- and the AQ-encoded cylindrical lenses. (C) 2000 Optical Society of America. OCIS codes: 050.0050, 050.1380, 050.1970.