%0 Journal Article
%T Beam shaping based on intermediate zone diffraction of a micro-aperture
%A Danyan Zeng
%A Zhijun Sun
%J Optica Applicata
%D 2008
%I 
%X We analyze optical diffraction of a micro-aperture (slit or hole) in a metal screen in the intermediate zone and report its application for beam focusing and collimating in micro-optics. Both finite-difference time-domain simulations and Rayleigh¨CSommerfeld diffraction formula were applied to calculate the intermediate-zone diffraction patterns. It is shown that, by controlling the aperture size, the focal length and depth can be adjusted in a very wide range, from subwavelength to tens of wavelengths, while the focal width maintains in an order of wavelength.
%K aperture
%K diffraction
%K beam shaping
%U http://www.if.pwr.wroc.pl/~optappl/pdf/2008/no3/optappl_3803p511.pdf