Patent ID: 7697191

Claim:
A phase contrast system for synthesizing a desired output electromagnetic field u(x″, y″, z″), comprising: a first phase modifying element for phase modulation of an input electromagnetic field by phasor values e iφ(x,y) , first Fourier or Fresnel optics, for Fourier or Fresnel transforming the phase modulated electromagnetic field, positioned in a propagation path of the phase modulated electromagnetic field, a spatial filter for filtering the Fourier or Fresnel transformed electromagnetic field by, in a region of spatial frequencies comprising DC in a Fourier or Fresnel plane, phase shifting with a predetermined phase shift value θ the Fourier or Fresnel transformed electromagnetic field in relation to a remaining part of the Fourier or Fresnel transformed electromagnetic field, and multiplying an amplitude of the phase shifted transformed electromagnetic field with a constant B, and in a region of remaining spatial frequencies in the Fourier or Fresnel plane, multiplying an amplitude of the Fourier or Fresnel transformed electromagnetic field with a constant A, second Fourier or Fresnel optics, for forming an electromagnetic field o(x′, y′) by Fourier or Fresnel transforming the filtered electromagnetic field, and a second phase modifying element for phase modulating the electromagnetic field o(x′, y′) into an electromagnetic field o(x′, y′)e iΨ(x′, y′) propagating as the desired output electromagnetic field u(x″, y″, z″).