Annular pupils, radial polarization, and superresolution.
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 (lambda = 488 nm). Radially polarized annular illumination of a solid-immersion lens can yield a focal spot smaller than 100 nm for lambda = 488 nm. Use of radially polarized illumination with pupil masks is discussed.
Sheppard
Colin J R
CJ
Division of Bioengineering, National University of Singapore, Engineering Drive, Singapore. biescjr@nus.edu.sg
Choudhury
Amarjyoti
A