US4547664A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Diffraction grating beam splitter in a laser resonator length control
Assignee: Carl Zeiss AG
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Filing: 1983-03-31
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Granted: 1985-10-15
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Expires: 2003-03-31
Abstract
Abstract The invention contemplates a beam splitter which consists of a phase grating (5) which transmits at zero order the greatest part of the radiation of a two-mode laser (1) and which diffracts a relatively small part of the radiation, symmetrically at 1 order and -1 order, respectively. The intensity of components of the radiation polarized perpendicular to each other and associated with the two modes is measured by detectors (11, 12) in front of which polarization sheets (9, 10) are arranged as analyzers, and outputs of the detectors are used to regulate the center frequency of the laser tube (1).
Inventors
- 👤 Peter Vogt
- 👤 Horst Kunzmann
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 15:21
CPC Classifications
G; G01; G01J; G01J4/00; G01J4/04; G02; G02B; G02B27/00; G02B27/10; G02B27/108; G02B27/1086; G02B27/1093; H; H01; H01S; H01S3/00; H01S3/10; H01S3/13; H01S3/139
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
118 words
In combination, a laser having a resonator emitting a laser beam, means for varying the length of the resonator, a beam expander comprising at least two lens elements, a diffraction grating on one of said lens elements, said grating transmitting at zero order nearly all of the beam intensity emitted from the resonator, and said grating diffracting from the relatively small remainder of the beam intensity at two higher orders and into two different regions offset from the path of zero-order transmission, cross-polarized analyzers positioned in the respective different regions, and means including separate detectors behind the respective analyzers and producing an electrical signal operatively connected to stabilize laser-beam frequency by correctively varying the length of the resonator.
Claim 2
Dependent Claim
118 words
In combination, a laser having a resonator emitting a laser beam, means for varying the length of the resonator, a beam expander comprising at least two lens elements, a diffraction grating on one of said lens elements, said grating transmitting at zero order nearly all of the beam intensity emitted from the resonator, and said grating diffracting from the relatively small remainder of the beam intensity at two higher orders and into two different regions offset from the path of zero-order transmission, cross-polarized analyzers positioned in the respective different regions, and means including separate detectors behind the respective analyzers and producing an electrical signal operatively connected to stabilize laser-beam frequency by correctively varying the length of the resonator.
Claim 3
Dependent Claim
16 words
The combination of claim 1, characterized by the fact that the grating is a transmission grating.
Claim 4
Dependent Claim
16 words
The combination of claim 1, characterized by the fact that the grating is a phase grating.
Claim 5
Dependent Claim
35 words
The combination of claim 1, characterized by the fact that the grating is a grating with symmetric groove profile which diffracts, in addition to the zero order, substantially only into plus and minus first orders.
Claim 6
Dependent Claim
34 words
The combination of claim 1, in which the two lens elements of said beam expander, the said diffraction grating, the said analyzers and the said detectors are all combined to form a single assembly.
References Cited (Backward Citations)
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1988-10-14 | 1989-04-15 | 1989-10-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1992-10-14 | 1993-04-15 | 1993-10-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1996-10-14 | 1997-04-15 | 1997-10-15 | $7700.00 | Window Closed / Lapsed |