Multilevel diffractive optical elements are necessary for achieving high-efficiency performance. Here the diffraction efficiency of a multilevel phase-only diffractive lens is analyzed. Approximate, as well as more accurate, approaches are presented. Both plane-wave and Gaussian illumination are discussed. It is shown that for many practical cases the diffraction efficiency can be determined by only a single parameter that takes into account the spatial bandwidth product as well as the focal length of the lens and the illumination wavelength. The analysis is based on the scalar theory and the thin-element approximation. Justification for doing this is presented. The results are valid for lenses with at least F/5.
© 2001 Optical Society of America
(050.1380) Diffraction and gratings : Binary optics
(050.1970) Diffraction and gratings : Diffractive optics
(220.3630) Optical design and fabrication : Lenses
(220.3740) Optical design and fabrication : Lithography
Uriel Levy, David Mendlovic, and Emanuel Marom, "Efficiency analysis of diffractive lenses," J. Opt. Soc. Am. A 18, 86-93 (2001)