Claims
- 1. An optical correlator correlating between incident optical signals, comprising one or more optical pulses each having a pulse width, said optical correlator comprising:
- a transmission line in close juxtaposition to a photoconductor,
- said optical correlator having an electrical non-linear response to said incident optical signals and having a response time,
- said electrical nonlinear response resulting from a voltage divider comprising the combination of said transmission line and said photoconductor,
- said response time of said electrical nonlinear response being less than the width of the narrowest pulse of said optical signals.
- 2. The optical correlator of claim 1 wherein said electrical non-linear response is less than twenty picoseconds.
- 3. The optical correlator of claim 1 wherein said electrical non-linear response is proportional to a second-order intensity autocorrelation function g.sup.(2) (.tau.).
- 4. The optical correlator of claim 1 wherein said correlator is a cross-correlator.
- 5. The optical correlator of claim 1 wherein said correlator is an auto-correlator.
- 6. The optical correlator of claim 1 wherein said photoconductor is positioned within said transmission line.
- 7. The optical correlator of claim 1 wherein said transmission line and said photoconductor are monolithically integrated on a substrate.
- 8. An optical metrology apparatus comprising:
- a) a source of optical radiation providing reference optical signals, comprising one or more optical pulses each having a pulse width; and
- b) an optical correlator positioned to receive said reference optical signals from said source of optical radiation and measurement optical signals received from an object, said optical correlator comprising a transmission line in close juxtaposition to a photoconductor,
- said optical correlator having an electrical non-linear response to said reference and said measurement optical signals and having a response time, said electrical non-linear response resulting from a voltage divider comprising the combination of said transmission line and said photoconductor,
- said response time of said electrical nonlinear response being less than the width of the narrowest pulse of said reference and said measurement optical signals.
- 9. The optical correlator of claim 8 wherein said optical correlator further includes a beamsplitter, said beamsplitter dividing each of said pulses of optical radiation into a first and a second pulse, said first optical pulse being reflected from an object prior to being combined with said second optical pulse in said optical correlator.
- 10. An absolute ranging apparatus comprising:
- a) a source of optical radiation providing reference optical signals, comprising one or more optical pulses each having a pulse width;
- b) an optical correlator positioned to receive said reference optical signals from said source of optical radiation and measurement optical signals received from an object, said optical correlator comprising a transmission line in close juxtaposition to a photoconductor, and
- c) an encoder for encoding selected pulses of said reference optical signals,
- d) said optical correlator having an electrical non-linear response to said reference and said measurement optical signals and having a response time, said electrical non-linear response resulting from a voltage divider comprising the combination of said transmission line and said photoconductor,
- e) said response time of said electrical nonlinear response being less than the width of the narrowest pulse of said reference and said measurement optical signals.
- 11. The absolute ranging apparatus of claim 10, wherein said encoder comprises a modulator.
- 12. The absolute ranging apparatus of claim 10, wherein said encoder comprises a second photoconductor positioned to receive said pulses of radiation reflected from said object.
- 13. A recognition system comprising:
- a) an optical metrology apparatus comprising:
- i) a source of optical radiation providing reference optical signals, comprising one or more optical pulses each having a pulse width; and
- ii) an optical correlator positioned to receive said reference optical signals from said source of optical radiation and interrogation optical signals received from an object, said optical correlator comprising a transmission line in close juxtaposition to a photoconductor,
- iii) said optical correlator having an electrical non-linear response to said reference and said interrogation optical signals and having a response time, said electrical non-linear response resulting from a voltage divider comprising the combination of said transmission line and said photoconductor,
- said response time of said electrical nonlinear response being less than the width of the narrowest pulse of said incident and reflected optical signals; and
- b) a computational system in electrical communication with said optical correlator,
- said computational system identifying an object in response to the correlation of said reference optical signals and said interrogation optical signals.
- 14. The apparatus of claim 11 wherein said computational system is a neural network.
RELATED APPLICATIONS
The present invention claims priority to Provisional Application U.S. Ser. No. 60/008,247 filed Dec. 6, 1995, the entire disclosure of which is incorporated herein by reference.
GOVERNMENT SUPPORT
This invention was made with government support under Contract Number F 19628-95-C-0002 awarded by the Department of the Air Force and Grant Number 9400334-DMR awarded by the National Science Foundation. The government has certain rights in the invention.
US Referenced Citations (2)
Number |
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4866660 |
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Sep 1989 |
|
4870295 |
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Sep 1989 |
|
Non-Patent Literature Citations (3)
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