MULTI-DIMENSIONAL FOURIER TRANSFORM OPTICAL PROCESSOR

• US 3,872,293 A
• Filed: 07/30/1973
• Issued: 03/18/1975
• Est. Priority Date: 01/07/1972
• Status: Expired due to Term

• Current Assignee: Eugene L. Green
• Original Assignee: Eugene L. Green
• Inventors: Green, Eugene L.
• Primary Examiner(s): Gruber, Felix D.
• Application Number:
  US05/384,151
• Time in Patent Office: 596 Days
• Field of Search: 235/181 350/160,96B,161,162SF 340/15.5VD
• US Class Current: 708/821
• CPC Class Codes: G06E 3/001 Analogue devices in which mathematical operations are carried out with the aid of optical or electro-optical elements optical elements per se G02B; devices consisting of a plurality of solid state components, including light sensitive semiconductor components, formed in or on a common substrate H01L27/14; electro-, magneto- or acousto-optics, non-linear optics G02F1/00; graph reading G06K11/00
• CPC Class Codes: G06E 3/005 using electro-optical or opto-electronic means

Abstract

A coherent beam of light is modulated by signals from an array of hydrophones. Multi-dimensional optical Fourier transform processing is accomplished in a sequence that includes optical Fourier transform and re-mapping operations that conserve phase and amplitude. In such optical processing of signals from the array the first or temporal Fourier plane of multichannel frequency analysis is scanned to perform a sequence of one or two-dimensional spatial transforms. The spatial transforms, each of which corresponds to a discrete acoustic frequency, are performed after re-mapping the frequency analyzed data into an optical space model of the acoustic array. The means for remapping the data is a set of dielectric wave guides. Alternatively, optical signals are physically measured and then re-mapped.

Claims

1. A multi-dimensional optical processor for processing a time sequence of data signals from a two-dimensional input comprising:

means for converting said data signals to light signals by modulating the amplitude and phase of a beam of light with said data signals, thus forming a modulated light beam;

first optical means for performing an integral transform on the light signals of said modulated light beam, obtaining an output of said first optical means;

means for re-mapping the output of said first optical means, preserving optical phase and amplitude thereof, thus obtaining re-mapped signals;

second optical means for integral transforming said re-mapped signals, obtaining an output of said second optical means; and

means for detecting coherently and storing the output of said second optical means.

2. The optical processor of claim 1 wherein said re-mapping means include dielectric wave guides.

3. The optical processor of claim 1 in which said re-mapping means further comprises a reference beam and a coherent detection means.

4. The optical processor of claim 1 which further comprises an optical scanner means for scanning said modulated light beam, generating an output having each element thereof corresponding to each element of said data signals, and said optical scanner means delivering the output thereof through an optical integral transform means to said means for detecting coherently.

5. The optical processor of claim 1 wherein a laser means provides said beam of lIght.

6. A multi-dimensional Fourier transform optical processor for processing a time sequence of data from an array of transducers comprising:

means for modulating a beam of light with signals from said transducers;

optical means for performing parallel one-dimensional Fourier transforms on said transducer signals in time domains, yielding as an output a coherent frequency analysis of said transducer signals preserving phase and amplitude thereof, thus forming frequency analyzed signals;

a set of optical dielectric wave guides at least equal in number to the number of transducer channels, said dielectric wave guide fibers conducting said frequency analyzed signals, preserving relative phase and amplitude, re-mapping said signals into a model of said array, thus forming re-mapped frequency analyzed signals;

means for scanning said re-mapped frequency analyzed signals at the output of said optical system, delivering said re-mapped frequency analyzed signals into said dielectric wave guides;

an optical system including means for performing a two-dimensional Fourier transform on said re-mapped frequency analyzed signals forming a sequence of two-dimensional Fourier transforms;

means for detecting and storing said sequence of two-dimensional Fourier transforms and constituting a three-dimensional Fourier transform yielding direction and frequency of signals received by said array.

7. A multi-dimensional Fourier transform optical processor for processing a time sequence of data signals from an array of transducers comprising:

means for modulating a beam of light with said data signals from said array of transducers;

a first optical means for performing parallel one-dimensional Fourier transforms on said data signals in a time domain, thus yielding as an output providing coherent frequency analysis of said data signals preserving phase and amplitude thereof;

means for detecting and integrating over time the output of said first optical means, preserving phase and amplitude information thereof, said detecting and integrating means including a reference optical beam superimposed on the output plane of said first optical means and a one-dimensional matrix of light sensing elements responsive to interaction of the frequency analyzed beam and the reference beam;

means for scanning the frequency analyzed signals over said matrix of light sensing elements and switching synchronously with the output of said scanning means, line by line, said re-mapped frequency analyzed and frequency analyzed signals forming a set of points modeling said array;

means for constructing an optical model for modulating the coherent light re-mapping signal frequency signals obtained by said detecting and integrating means;

second optical means for performing a two-dimensional Fourier transform on such coherently re-mapped signals, and obtaining an output thereof; and

means for detecting and storing the output of second optical means.

8. The optical processor of claim 7 wherein said matrix of light sensing elements of said detecting and integrating means is two-dimensional.

9. The optical processor of claim 7 wherein said scanning means is electronic for re-mapping signals into a model of said array by scanning each frequency position to provide an optical model of said array signals at each frequency.

10. A multi-dimensional optical processor for performing a sequence of optical operations on a two-dimensional data input by coherent re-mapping of data points between processing stages with preservation of optical phase and amplitude thereof and dynamic phase and amplitude filtering in conjunction with the coherent re-mapping, said processor comprising:

first modulating means for modulating light signals with such data;

first optical means for performing integral transform on the output of said first modulating means;

means for coherently re-mapping the output of said first optical integral trAnsforming means and filtering coherently the output of said first optical integral transforming means, obtaining an output thereof;

means for detecting the output of said re-mapping and filtering means and for obtaining an output thereof;

second modulating means for modulating light with the output of said detecting means;

second optical means for further integral transforming said signals; and

means for detecting and storing the output of said second optical means.

11. The optical processor of claim 10 wherein said coherently re-mapping and filtering means are dielectric wave guides.

12. The optical processor of claim 10 wherein said coherently re-mapping and filtering means include a reference beam and coherent detection means and said filtering means performing directly on the optical signals by a light modulating means before coherent detection thereof.

13. The optical processor of claim 10 wherein said means for coherently re-mapping and filtering the output of said first optical means is electrical.

14. The optical processor of claim 10 wherein said means for filtering the output of said first optical means includes modulating means of the output of said second optical means.