US3627422A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Means for avoiding locking in ring lasers
Assignee: Varian Medical Systems Inc
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Filing: 1965-06-21
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Granted: 1971-12-14
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Expires: 1985-06-21
Abstract
Abstract Means are disclosed for frequency modulating opposing modes in a ring laser assembly whereby locking is minimized or eliminated. The use of three types of modulators comprising an acoustic generator, a light shutter and an electro-optic crystal are described. In each case, the modulators are driven in accordance with a time-varying signal provided by a signal generator.
Inventors
- 👤 Marvin Chodorow
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-22 20:43
CPC Classifications
G; G01; G01C; G01C19/00; G01C19/58; G01C19/64; G01C19/66; G01C19/68
Claims Analysis
Total Claims: 17
Claim 1
Independent Claim
154 words
A rotary sensor having a closed path within which radiation circulates for measuring rate of rotation comprising: laser means having a laser medium disposed within and as a part of said path for providing radiation in different directions; means for reflecting said radiation to form said closed path wherein said radiation resonates in two opposing modes; modulating means disposed in said closed path for modulating said circulating radiation at a certain frequency such that the radiation of the two circulating modes does not have the same frequency at the same time in the laser medium to prevent frequency locking of said two opposite modes within the laser medium of the radiation-providing means; oscillator means coupled to said modulating means for applying a time-varying signal of the certain frequency to said modulating means; and means including a semitransparent means coupled to said closed path for detecting the frequencies of each of said two opposing modes.
Claim 2
Dependent Claim
154 words
A rotary sensor having a closed path within which radiation circulates for measuring rate of rotation comprising: laser means having a laser medium disposed within and as a part of said path for providing radiation in different directions; means for reflecting said radiation to form said closed path wherein said radiation resonates in two opposing modes; modulating means disposed in said closed path for modulating said circulating radiation at a certain frequency such that the radiation of the two circulating modes does not have the same frequency at the same time in the laser medium to prevent frequency locking of said two opposite modes within the laser medium of the radiation-providing means; oscillator means coupled to said modulating means for applying a time-varying signal of the certain frequency to said modulating means; and means including a semitransparent means coupled to said closed path for detecting the frequencies of each of said two opposing modes.
Claim 3
Dependent Claim
20 words
A rotary sensor as in claim 1, wherein the radiation-providing means is a gas laser disposed in the closed path.
Claim 4
Dependent Claim
22 words
A rotary sensor as in claim 1, wherein the reflecting means includes mirrors disposed at the corners of such polygonal closed path.
Claim 5
Dependent Claim
22 words
A rotary sensor as in claim 1, wherein said detecting means includes a photodetector and mixer circuit for obtaining the difference signal.
Claim 6
Dependent Claim
33 words
A rotary sensor as in claim 1, wherein the modulating means includes a signal generator for providing microwave frequencies, and a crystal disposed in such closed path and coupled to said signal generator.
Claim 7
Dependent Claim
104 words
A rotary sensor for measuring rate of rotation comprising: at least one radiation device spaced in a polygonal closed path for providing radiation in opposite directions in such path; reflecting mirrors disposed at the corners of the polygon formed by the closed path, at least one of such mirrors being semitransparent; light shutter means for forming and passing a pulse of radiation when open, disposed In the closed path; signal generator means coupled to said light shutter means for modulating said shutter means so that the opposing pulses of radiation pass through the shutter means simultaneously and at different time through said radiation device.
Claim 8
Dependent Claim
104 words
A rotary sensor for measuring rate of rotation comprising: at least one radiation device spaced in a polygonal closed path for providing radiation in opposite directions in such path; reflecting mirrors disposed at the corners of the polygon formed by the closed path, at least one of such mirrors being semitransparent; light shutter means for forming and passing a pulse of radiation when open, disposed In the closed path; signal generator means coupled to said light shutter means for modulating said shutter means so that the opposing pulses of radiation pass through the shutter means simultaneously and at different time through said radiation device.
Claim 9
Dependent Claim
27 words
A rotary sensor as in claim 6, wherein said light shutter means includes a plurality of light shutters spaced equidistantly from a point in said closed path.
Claim 10
Dependent Claim
69 words
A rotary sensing device comprising: laser means having a laser medium for providing opposing modes of radiation; reflecting means disposed to deflect such radiation into a closed path including said laser medium; means for frequency modulating said modes in accordance with a time-varying signal of a certain frequency to shift the frequency of such modes with respect to one another in said laser medium, whereby frequency lock-in is avoided.
Claim 11
Dependent Claim
69 words
A rotary sensing device comprising: laser means having a laser medium for providing opposing modes of radiation; reflecting means disposed to deflect such radiation into a closed path including said laser medium; means for frequency modulating said modes in accordance with a time-varying signal of a certain frequency to shift the frequency of such modes with respect to one another in said laser medium, whereby frequency lock-in is avoided.
Claim 12
Dependent Claim
45 words
A rotary sensing device as in claim 8, wherein said means for frequency modulating such opposing modes includes means for varying the frequency along each mode pattern so that no overlapping portions of two opposing modes inside the laser means have the same instantaneous frequency.
Claim 13
Dependent Claim
31 words
A rotary sensing device as in claim 8, wherein the frequency-modulating means comprises an electro-optic modulator crystal disposed in such path, and means for applying an electric field to said crystal.
Claim 14
Dependent Claim
134 words
A ring laser assembly including first and second closed-loop radiation paths comprising: a laser for providing coherent radiation; reflection means disposed in polygonal arrangement for directing such radiation along said first and said second closed paths, with components in opposing directions; modulator means coupling said first and said second closed path for diffracting and deflecting a portion of such opposing radiation components in said first path into said second path to form a second closed path of opposing components, the frequencies of the opposing components in said second path being mutually different and different from the frequencies of the components in said first path; means for detecting the difference in the frequencies of the components in the second path; and means for utilizing such difference to measure the rate of rotation of the assembly.
Claim 15
Dependent Claim
134 words
A ring laser assembly including first and second closed-loop radiation paths comprising: a laser for providing coherent radiation; reflection means disposed in polygonal arrangement for directing such radiation along said first and said second closed paths, with components in opposing directions; modulator means coupling said first and said second closed path for diffracting and deflecting a portion of such opposing radiation components in said first path into said second path to form a second closed path of opposing components, the frequencies of the opposing components in said second path being mutually different and different from the frequencies of the components in said first path; means for detecting the difference in the frequencies of the components in the second path; and means for utilizing such difference to measure the rate of rotation of the assembly.
Claim 16
Dependent Claim
97 words
A ring laser assembly including first and second closed-loop radiation paths comprising: a gas laser for providing coherent radiation; reflecting mirrors disposed in polygonal arrangement for directing such radiation along said first and said second closed paths, with components in opposing directions; acoustic modulator means coupling said first closed paths for diffracting and deflecting a portion of such opposing radiation in said first path into said second path being mutually different, and different from the frequencies of the components in said first path; means for utilizing such difference to measure the rate of rotation of the assembly.
Claim 17
Dependent Claim
97 words
A ring laser assembly including first and second closed-loop radiation paths comprising: a gas laser for providing coherent radiation; reflecting mirrors disposed in polygonal arrangement for directing such radiation along said first and said second closed paths, with components in opposing directions; acoustic modulator means coupling said first closed paths for diffracting and deflecting a portion of such opposing radiation in said first path into said second path being mutually different, and different from the frequencies of the components in said first path; means for utilizing such difference to measure the rate of rotation of the assembly.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1974-12-13 | 1975-06-14 | 1975-12-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-12-13 | 1979-06-14 | 1979-12-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-12-13 | 1983-06-14 | 1983-12-14 | $7700.00 | Window Closed / Lapsed |