Abstract
Recently, Dorn, et al. [Phys. Rev. Lett. 91, 233901 (2003)] demonstrated the significance of radially polarized doughnut beams in obtaining very small focal spots (with an area of ) with high-numerical-aperture (NA) aplanatic microscope objectives. We propose two simple alternative ways to focus such radially polarized beams: a parabolic mirror and a flat diffractive lens. Because of their large apodization factor for a high NA, a significant further reduction in spot area (up to a factor of 1.76 at a NA of 1) compared with the aplanatic system can be achieved.
© 2004 Optical Society of America
Full Article | PDF ArticleMore Like This
Nándor Bokor and Nir Davidson
Opt. Lett. 29(17) 1968-1970 (2004)
Ram Oron, Jacob L. Guedalia, Nir Davidson, Asher A. Friesem, and Erez Hasman
Opt. Lett. 25(7) 439-441 (2000)
Colin J. R. Sheppard and Amarjyoti Choudhury
Appl. Opt. 43(22) 4322-4327 (2004)