Optical correlator
OwnerJacques E. Ludmaninventor
Life of this patent
Estimating the term…
Abstract
An optical correlator having a series of optical elements necessary for providing the comparison or correlation of incoming optical signals and for providing a readout beam representive of the correlation between the input signals; and a detection system which is capable of rapidly and reliably detecting intensity peaks in the readout beam. These intensity peaks establish the actual correlation between the optical input signals. The detection system incorporates therein a pair of optical fibers, one of which having associated therewith an electro-optic component for effectively varying the length of that fiber. By varying the effective length of one of the fibers, an intensity detector can provide an output of the intensity peaks necessary in making the actual correlation determination between the optical input signals.
Claims10
An optical correlator comprising:
- means for comparing a pair of optical signals and providing a readout beam formed of a plurality of components, each of said components having wavefronts associated therewith and varying in intensity representative of said optical signals;
- and
- means for detecting said wavefronts of said components of said readout beam in order to establish a correlation between said optical signals, said detecting means including:
- a pair of optical fibers optically interposed within said readout beam, each of said optical fibers having substantially the same optical path length,
- means optically associated with said pair of optical fibers for combining said optical fibers to form a single optical output path,
- means operably associated with one of said optical fibers for varying the effective optical path length of said one optical fiber, and
- means optically aligned with said optical output path for detecting periodic variations in intensities of said wavefronts of said components of said readout beam;
- whereby, conventional Fourier spectroscopy techniques can be applied to said detected periodic intensities in order to establish said correlation between said optical signals.
A method of correlating a pair of optical signals comprising the steps of:
- (a) comparing said pair of optical signals and providing a readout beam formed of a plurality of components having wavefronts associated therewith, said wavefronts of one component varying in intensity from the wavefronts of another component, and being representative of said optical signals;
- (b) interposing a pair of optical fibers of substantially the same optical length within said readout beam;
- (c) altering the effective optical length of one of said fibers in order to detect a periodic intensity signal;
- (d) detecting said periodic intensity signal;
- (e) applying techniques of conventional Fourier spectroscopy to said periodic intensity signal in order to extract frequencies therefrom, each of said frequencies corresponding to a component of said readout beam;
- and
- (f) relating the most intense of said extracted frequencies to a correlation component corresponding to a correlation between said pair of optical signals.
Dependencies are inferred from the claim text.