US4765740A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Optical apparatus based on measurement of phase or frequency shift of an oscillating beam, particularly useful as an optical gyro
Assignee: DEVELOPMENT FOUNDATION Ltd TECHNION CITY HAIFA 32 000 ISRAEL
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Filing: 1986-01-23
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Granted: 1988-08-23
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Expires: 2006-01-23
Abstract
Abstract Optical apparatus, particularly useful as an optical gyro for measuring rotation, comprises a light source, an optical system defining a closed-loop optical path, an optical-wave-mixer producing form the light source beam an oscillating beam in the closed-loop optical path, and a circuit for measuring the phase or frequency shift produced in the oscillating beam by the optical-wave-mixer resulting from the non-reciprocal or reciprocal phase-shift thereof. A mathematical analysis is set forth showing how the non-reciprocal phase-shift is related to the frequency shift, so that the frequency shift provides a measurement of the non-reciprocal phase-shift, which depends on the rotation of the closed-loop ring optical path, thereby enabling the apparatus to serve as an optical gyro.
Inventors
- 👤 Baruch Fischer
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 20:59
CPC Classifications
G; G01; G01C; G01C19/00; G01C19/58; G01C19/64
Claims Analysis
Total Claims: 32
Claim 1
Independent Claim
65 words
Optical apparatus comprising: an optical system defining a closed-loop optical path; a light source producing a single pumping beam outside said closed-loop optical path; an optical-wave-mixer producing from said single pumping beam an oscillating beam in said closed-loop optical path; and means for measuring the phase or frequency shift produced in said oscillating beam by said optical-wave-mixer resulting from the non-reciprocal or reciprocal phase-shift thereof.
Claim 2
Dependent Claim
65 words
Optical apparatus comprising: an optical system defining a closed-loop optical path; a light source producing a single pumping beam outside said closed-loop optical path; an optical-wave-mixer producing from said single pumping beam an oscillating beam in said closed-loop optical path; and means for measuring the phase or frequency shift produced in said oscillating beam by said optical-wave-mixer resulting from the non-reciprocal or reciprocal phase-shift thereof.
Claim 3
Dependent Claim
25 words
Apparatus according to claim 1, further including means for deriving from said measured frequency shift a measurement of the rotation of said closed-loop optical path.
Claim 4
Dependent Claim
29 words
Apparatus according to claim 1, further including means for deriving from said measured frequency shift a measurement of the magnetic field to which said closed-loop optical path is subjected.
Claim 5
Dependent Claim
22 words
Apparatus according to claim 1, wherein said optical-wave-mixer is a four-wave mixer and produces counter-propagating oscillating beams in said closed-loop optical path.
Claim 6
Dependent Claim
14 words
Apparatus according to claim 1, wherein said closed-loop optical path comprises an optical fiber.
Claim 7
Dependent Claim
13 words
Apparatus according to claim 5, wherein said optical fiber is a multi-mode fiber.
Claim 8
Dependent Claim
28 words
Apparatus according to claim 1, wherein said single pumping beam passes through said optical-wave-mixer in one direction and is fed back completely or partially to the said optical-wave-mixer.
Claim 9
Dependent Claim
15 words
Apparatus according to claim 1, wherein said single pumping beam passes through an optical fiber.
Claim 10
Dependent Claim
22 words
Apparatus according to claim 7, wherein said optical-wave-mixer is a four-wave mixer and produces counter-propagating oscillating beams in the closed-loop optical path.
Claim 11
Dependent Claim
27 words
Apparatus according to claim 1, wherein said optical-wave-mixer is a two-wave mixer producing from said single pumping beam a unidirectionally oscillating beam in said closed-loop optical path.
Claim 12
Dependent Claim
12 words
Apparatus according to claim 1, wherein said optical-wave-mixer is a photorefractive crystal.
Claim 13
Dependent Claim
21 words
Apparatus according to claim 11, including means for producing an electric field bias on said crystal to control the frequency shift.
Claim 14
Dependent Claim
27 words
Apparatus according to claim 11, further including means for controlling the intensity and/or polarization of said single pumping beam, to thereby control the sensitivity of the apparatus.
Claim 15
Dependent Claim
36 words
Apparatus according to claim 11, further including means for adjusting the relative orientation and angle of said single pumping beam and thereby the coupling coefficient of said crystal, to thereby control the sensitivity of the apparatus.
Claim 16
Dependent Claim
31 words
Apparatus according to claim 11, further including means for controlling the transmittivity and/or polarization of the single pumping beam in the closed-loop optical path and thereby the sensitivity of the apparatus.
Claim 17
Dependent Claim
12 words
Apparatus according to claim 1, wherein said light source is a laser.
Claim 18
Dependent Claim
67 words
Frequency shifter apparatus, comprising: an optical system defining a closed-loop optical path: a light source producing a single pumping beam outside said closed-loop optical path; an optical-wave-mixer producing from said single pumping beam an oscillating beam in said closed-loop optical path; and means for producing a predetermined reciprocal and/or non-reciprocal phase-shift in said oscillating beam in order to shift the frequency relative to said single pumping beam.
Claim 19
Dependent Claim
67 words
Frequency shifter apparatus, comprising: an optical system defining a closed-loop optical path: a light source producing a single pumping beam outside said closed-loop optical path; an optical-wave-mixer producing from said single pumping beam an oscillating beam in said closed-loop optical path; and means for producing a predetermined reciprocal and/or non-reciprocal phase-shift in said oscillating beam in order to shift the frequency relative to said single pumping beam.
Claim 20
Dependent Claim
22 words
Apparatus according to claim 17, wherein said optical-wave-mixer is a four-wave mixer and produces counter-propagating oscillating beams in said closed-loop optical path.
Claim 21
Dependent Claim
14 words
Apparatus according to claim 17, wherein said closed-loop optical path comprises an optical fiber.
Claim 22
Dependent Claim
13 words
Apparatus according to claim 19, wherein said optical fiber is a multi-mode fiber.
Claim 23
Dependent Claim
28 words
Apparatus according to claim 17, wherein said single pumping beam passes through said optical-wave-mixer in one direction and is fed back completely or partially to the said optical-wave-mixer.
Claim 24
Dependent Claim
22 words
Apparatus according to claim 20, wherein said optical-wave-mixer is a four-wave mixer and produces counter-propagating oscillating beams in the closed-loop optical path.
Claim 25
Dependent Claim
15 words
Apparatus according to claim 17, wherein said single pumping beam passes through an optical fiber.
Claim 26
Dependent Claim
27 words
Apparatus according to claim 17, wherein said optical-wave-mixer is a two-wave mixer producing from said single pumping beam a unidirectionally oscillating beam in said closed-loop optical path.
Claim 27
Dependent Claim
12 words
Apparatus according to claim 17, wherein said optical-wave-mixer is a photorefractive crystal.
Claim 28
Dependent Claim
22 words
Apparatus according to claim 25, further including means for producing an electric field bias on said crystal to control the frequency shift.
Claim 29
Dependent Claim
27 words
Apparatus according to claim 25, further including means for controlling the intensity and/or polarization of said single pumping beam, to thereby control the sensitivity of the apparatus.
Claim 30
Dependent Claim
36 words
Apparatus according to claim 25, further including means for adjusting the relative orientation and angle of said single pumping beam and thereby the coupling coefficient of said crystal, to thereby control the sensitivity of the apparatus.
Claim 31
Dependent Claim
31 words
Apparatus according to claim 25, further including means for controlling the transmittivity and/or polarization of the single pumping beam in the closed-loop optical path and thereby the sensitivity of the apparatus.
Claim 32
Dependent Claim
12 words
Apparatus according to claim 17, wherein said light source is a laser.
References Cited (Backward Citations)
US4410275A
Cited
US4659223A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1991-08-23 | 1992-02-22 | 1992-08-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-08-23 | 1996-02-22 | 1996-08-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-08-23 | 2000-02-22 | 2000-08-23 | $7700.00 | Window Closed / Lapsed |