Patent ID: 6163391
Filing Date: 2000-12-19
Classification: G03H,G11B

Abstract:
Apparatus for holographic recording of information, wherein:a) the apparatus comprises a lens or lens system, to be referred to as the Fr lens, so situated that: light from an object beam enters the Fr lens after being modulated by an object, and light leaving the Fr lens impinges on a recording medium situated at a Fourier transform plane of the object with respect to the FT lens;b) the apparatus further comprises an optical element or optical system, to be referred to as the power optic, that adds convergence or divergence to the object beam before the object beam enters the FT lens;c) absent the power optic and absent the object, the FT lens tends to bring the object beam to a focal spot in the Fourier transform plane, said spot to be referred to as the object focus; andd) the power optic is adapted to shift the object focus out of the Fourier transform plane.