Superresolution phase-only pupil filters designed to utilize the degrees of freedom made available by diffractive optics technology are investigated theoretically. These so-called diffractive superresolution elements improve the quality of the superresolved diffraction pattern from the point of view of Strehl ratio, reduction of the spot size, control of the sidelobe effects, optimization procedures, and fabrication tolerances. The performance of these elements is studied, and the nature of the solutions obtainable with binary and multiple-phase structures is analyzed. Design considerations and solutions for applications such as confocal scanning microscopy and optical data storage are presented. Optimization of the degrees of freedom to satisfy desired constraints is discussed and compared with other methods.
© 1997 Optical Society of America
Tasso R. M. Sales and G. Michael Morris, "Diffractive superresolution elements," J. Opt. Soc. Am. A 14, 1637-1646 (1997)