DIFFRACTIVE SUPERRESOLUTION ELEMENTS

Superresolution phase-only pupil filters designed to utilize the degre es of freedom made available by diffractive optics technology are inve stigated theoretically. These so-called diffractive superresolution el ements improve the quality of the superresolved diffraction pattern fr om the point of view of Strehl ratio, reduction of the spot size, cont rol of the sidelobe effects, optimization procedures, and fabrication tolerances. The performance of these elements is studied, and the natu re of the solutions obtainable with binary and multiple-phase structur es is analyzed. Design considerations and solutions for applications s uch as confocal scanning microscopy and optical data storage are prese nted. Optimization of the degrees of freedom to satisfy desired constr aints is discussed and compared with other methods. (C) 1997 Optical S ociety of America.