Holographic optical processing method and apparatus
First Claim
1. A method of performing optical processing on optical information corresponding to a subject disposed within a subject plane, comprising the steps of:
- directing a first coherent beam of light at the subject such that said light is diffracted, reflected and/or transmitted thereby, whereafter said beam contains optical information regarding the subject;
focusing said beam containing said subject information so as to define a Fourier transform plane and to image said information within an image plane beyond said transform plane;
disposing means for recording a hologram thereon at or near said image plane so as to receive thereon said beam containing said subject information;
directing a second coherent beam of light onto said recording means from a first direction so as to form an interference pattern with said first beam containing said subject information;
recording a hologram of said subject information on said recording means;
directing said second beam to said recording means from a direction conjugate to said first direction for diffraction thereby to the subject plane in a direction exactly opposite to that travelled by said first beam containing said subject information, whereby said Fourier transform is redefined at said transform plane and said subject information is carried within said second beam to the subject plane; and
manipulating said subject information contained within one of said beams at said transform plane.
3 Assignments
0 Petitions
Accused Products
Abstract
A method and apparatus for performing optical processing on optical information corresponding to a subject (66) combines known optical processing techniques with holography. A reverse ray-trace holographic system is provided so that the image reconstruction beam (90) passes through the optical system in a direction exactly opposite to that travelled by the subject beam (50) during recording of the hologram (88). Aberrations introduced by the system optics are then completely compensated for, allowing use of lower quality optical components. A single large-aperture lens (68) is used to define a Fourier transform of the optical subject information as the hologram (88) is recorded or the image reconstructed, and the subject information is manipulated within the Fourier transform plane (91).
10 Citations
21 Claims
-
1. A method of performing optical processing on optical information corresponding to a subject disposed within a subject plane, comprising the steps of:
-
directing a first coherent beam of light at the subject such that said light is diffracted, reflected and/or transmitted thereby, whereafter said beam contains optical information regarding the subject; focusing said beam containing said subject information so as to define a Fourier transform plane and to image said information within an image plane beyond said transform plane; disposing means for recording a hologram thereon at or near said image plane so as to receive thereon said beam containing said subject information; directing a second coherent beam of light onto said recording means from a first direction so as to form an interference pattern with said first beam containing said subject information; recording a hologram of said subject information on said recording means; directing said second beam to said recording means from a direction conjugate to said first direction for diffraction thereby to the subject plane in a direction exactly opposite to that travelled by said first beam containing said subject information, whereby said Fourier transform is redefined at said transform plane and said subject information is carried within said second beam to the subject plane; and manipulating said subject information contained within one of said beams at said transform plane. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8)
-
-
9. Apparatus for performing optical processing on optical information corresponding to a subject disposed within a subject plane, comprising:
-
a source for generating a substantially coherent beam of light; means for dividing said beam into a first beam and a second beam; means for directing said first beam to the subject such that said beam is diffracted, reflected and/or transmitted thereby, whereafter said beam contains optical information regarding the subject; means for recording a hologram of the subject thereon; means for passing therethrough said first beam containing said subject information, focusing said beam to define a Fourier transform within a transform plane, and imaging said beam onto or near said recording means; means for directing said second beam to said recording means from a first direction at a predetermined angle of incidence thereon so as to form an interference pattern; and means for directing said second beam to said recording means in a direction conjugate to said first direction for diffraction thereby into said lens in a direction exactly opposite to that travelled by said first beam therethrough, so that said subject information is carried within said second beam and a holographic image is reconstructed at said subject plane;
means for manipulating said subject information contained within one of said beams at said Fourier transform plane. - View Dependent Claims (10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21)
-
Specification