An annular pupil, which can be used to produce a Bessel beam, when combined with radially polarized illumination promises improvements in microscope resolution, increased packing density for optical storage, and finer optical lithography. When combined with a circular detection pupil in confocal microscopy a point-spread function 112 nm wide results (λ = 488 nm). Radially polarized annular illumination of a solid-immersion lens can yield a focal spot smaller than 100 nm for λ = 488 nm. Use of radially polarized illumination with pupil masks is diskussed.
© 2004 Optical Society of America
Original Manuscript: December 22, 2003
Revised Manuscript: April 22, 2004
Published: August 1, 2004
Colin J. R. Sheppard and Amarjyoti Choudhury, "Annular pupils, radial polarization, and superresolution," Appl. Opt. 43, 4322-4327 (2004)