US3697181A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Ring laser having amplitude and phase controlled crossed-beam anti-locking feedback
Assignee: Unisys Corp
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Filing: 1967-03-14
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Granted: 1972-10-10
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Expires: 1987-03-14
Abstract
Abstract A ring laser provided with at least one mirror external to the ring cavity for reflecting energy from one of the two counterrotating laser beams back into the ring to couple to the other beam. The mirror is arranged to have varying reflectivity along one of its dimensions and is positioned along said dimension (to vary the amplitude of feedback) and in a direction perpendicular thereto (to vary the phase of feedback). Each of the counterrotating laser beams is extracted from the cavity and the amplitude modulation thereon (due to cross-beam coupling) is detected. If two external mirrors are used, each is positioned to eliminate the amplitude modulation on a respective extracted beam. If only one external mirror is used, it is positioned to make the amplitude modulation on one extracted beam equal in amplitude and opposite in phase to the amplitude modulation on the other extracted beam.
Inventors
- 👤 Warren M Macek
- 👤 Chao Chen Wang
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 09:35
CPC Classifications
G; G01; G01C; G01C19/00; G01C19/58; G01C19/64; G01C19/66
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
147 words
A ring laser producing two counterrotating laser beams, said laser beams being extracted and made available along respective paths outside the ring cavity of said laser, said extracted beams being amplitude modulated due to crosscoupling between said laser beams inside said cavity, first means located outside said cavity along one of said paths for redirecting energy from one of said extracted beams back into said cavity in the direction of the other of said beams so that energy from said one beam is coupled to said other beam inside said cavity, null-seeking control means for controlling said first means to vary the redirected energy, and second means located along another of said paths for detecting the amplitude modulation on the other of said extracted beams and producing an output signal in response thereto, said output signal being applied to said control means to vary said redirected energy.
Claim 2
Dependent Claim
147 words
A ring laser producing two counterrotating laser beams, said laser beams being extracted and made available along respective paths outside the ring cavity of said laser, said extracted beams being amplitude modulated due to crosscoupling between said laser beams inside said cavity, first means located outside said cavity along one of said paths for redirecting energy from one of said extracted beams back into said cavity in the direction of the other of said beams so that energy from said one beam is coupled to said other beam inside said cavity, null-seeking control means for controlling said first means to vary the redirected energy, and second means located along another of said paths for detecting the amplitude modulation on the other of said extracted beams and producing an output signal in response thereto, said output signal being applied to said control means to vary said redirected energy.
Claim 3
Dependent Claim
20 words
A ring laser as defined in claim 1 wherein said null-seeking control means varies the amplitude of the redirected energy.
Claim 4
Dependent Claim
20 words
A ring laser as defined in claim 1 wherein said null-seeking control means varies the phase of the redirected energy.
Claim 5
Dependent Claim
23 words
A ring laser as defined in claim 1 wherein said null-seeking control means varies the amplitude and the phase of the redirected energy.
Claim 6
Dependent Claim
33 words
A ring laser as defined in claim 1 wherein said output signal is applied to said control means to vary said redirected energy so that said amplitude modulation is reduced to a minimum.
Claim 7
Dependent Claim
90 words
A ring laser as defined in claim 1 and further including third means located along another of said paths for detecting the amplitude modulation on said one of said extracted beams and producing an output signal in response thereto, both said outpuT signals from said second and third means being applied to said control means to vary said redirected energy so that the amplitude modulation on one of said beams is made equal in amplitude and opposite in phase to the amplitude modulation of the other of said laser beams.
References Cited (Backward Citations)
US3316348A
Cited
US3323411A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-10-10 | 1976-04-10 | 1976-10-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-10-10 | 1980-04-10 | 1980-10-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-10-10 | 1984-04-10 | 1984-10-10 | $7700.00 | Window Closed / Lapsed |