US4199226A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Laser transmitting and receiving device
Assignee: University of Bern
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Filing: 1978-03-16
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Granted: 1980-04-22
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Expires: 1998-03-16
Abstract
Abstract A laser for the production and radiation of monochromatic light to a first polarizer arranged in the beam path of a resonator of the laser and operative to pass one of two light beam components linearly polarized perpendicularly to one another and to deflect the other linearly polarized component out of the resonator onto a photodetector for detecting that reflected part of the radiated light. A second polarizer is arranged in the direction of radiation of the light beam, behind a decoupling mirror of the resonator, and is operative to convert linearly-polarized light into circularly-polarized light. Adjacent the second polarizer in the direction of radiation is a collimator consisting of an optical system for widening the transmission beam to a remote reflector and narrowing the reflected beam received from the remote reflector back into the second polarizer and the resonator from which it is deviated onto the photodetector.
Inventors
- 👤 Heinz P. Weber
- 👤 Claude Voumard
- 👤 Rene P. Salathe
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 16:55
CPC Classifications
H; H04; H04B; H04B10/00; H04B10/40; G; G01; G01B; G01B11/00; G01S; G01S7/00; G01S7/48; G01S7/481; G01S7/4811; G01S7/4812; G01S7/4814; G01S7/499; G02; G02B; G02B27/00; G02B27/10; G02B27/12; G02B27/28; G02B27/283; G02B6/00; G02B6/24; G02B6/42; G02B6/4201; G02B6/4246; H01; H01S; H01S3/00; H01S3/05; H01S3/08; H01S3/08004
Claims Analysis
Total Claims: 16
Claim 1
Independent Claim
172 words
A transmission and reception device comprising a laser for the production and radiation of monochromatic light, having an active medium disposed within an optical resonator, said resonator being supportive of a light beam and having a decoupling mirror for the exit of the light beam; a photodetector for detecting a reflected part of the radiated light beam; a polarizer arranged in the beam path of said resonator and a polarization converter arranged outside said resonator in the beam path of the radiated light, said polarizer being operative to pass one of two light beam components linearly polarized perpendicularly to one another and to deflect the other linearly polarized component out of the resonator onto the photodetector and said polarization converter being operative to convert linearly-polarized light into circularly-polarized light and vice versa; and a filter arranged in the beam path of said resonator, between said polarizer and said decoupling mirror, said filter being operative to pass a spectral range which lies in and is smaller than the amplification range of the laser.
Claim 2
Dependent Claim
172 words
A transmission and reception device comprising a laser for the production and radiation of monochromatic light, having an active medium disposed within an optical resonator, said resonator being supportive of a light beam and having a decoupling mirror for the exit of the light beam; a photodetector for detecting a reflected part of the radiated light beam; a polarizer arranged in the beam path of said resonator and a polarization converter arranged outside said resonator in the beam path of the radiated light, said polarizer being operative to pass one of two light beam components linearly polarized perpendicularly to one another and to deflect the other linearly polarized component out of the resonator onto the photodetector and said polarization converter being operative to convert linearly-polarized light into circularly-polarized light and vice versa; and a filter arranged in the beam path of said resonator, between said polarizer and said decoupling mirror, said filter being operative to pass a spectral range which lies in and is smaller than the amplification range of the laser.
Claim 3
Dependent Claim
16 words
A device as set forth in claim 1, in which said filter is a Fabry-Perot etalon.
Claim 4
Dependent Claim
96 words
A device as set forth in claim 1, including a second filter arranged between said polarizer and said photodetector, said second filter having a spectral pass range of which is the same as or greater than the band width of the radiated light beam, the device also being provided with a second polarizer disposed in the path of the light beam component deflected out of the resonator by said first polarizer and operative to absorb any component of light polarized perpendicularly to the deflected beam or to cause deviation of said component away from said photodetector.
Claim 5
Dependent Claim
20 words
A device as set forth in claim 1, in which said polarizer comprises a polarizing prism made of double-refracting material.
Claim 6
Dependent Claim
17 words
A device as set forth in claim 1, in which said polarization converter is a quarter-wave plate.
Claim 7
Dependent Claim
24 words
A device as set forth in claim 5, in which said decoupling mirror comprises a reflecting layer which is applied to the quarter-wave plate.
Claim 8
Dependent Claim
47 words
A device as set forth in claim 1, including a collimator arranged outside said resonator in the beam path of the radiated light, said collimator being operative to widen the radiated light beam and to reduce the width of a reflected part of the radiated light beam.
Claim 9
Dependent Claim
44 words
A device as set forth in claim 1, in which said laser is a semiconductor laser with an external resonator, said decoupling mirror being spaced from the semiconductor active medium and said polarizer being disposed between the semiconductor active medium and the decoupling mirror.
Claim 10
Dependent Claim
25 words
A device as set forth in claim 8 in which that end face of the semiconductor active medium which faces said decoupling mirror is dereflected.
Claim 11
Dependent Claim
20 words
A device as set forth in claim 9, in which the reflectivity of said decoupling mirror is less than 30%.
Claim 12
Dependent Claim
16 words
A device as set forth in claim 1, in which said laser is a liquid laser.
Claim 13
Dependent Claim
30 words
A device as set forth in claim 1, in which said filter is tunable, such that its spectral pass range may be shifted in the amplification range of the laser.
Claim 14
Dependent Claim
17 words
A device as set forth in claim 1, in which said laser is a homogeneously widened laser.
Claim 15
Dependent Claim
17 words
A device as set forth in claim 1, in which said polarizer is a dielectric multilayer polarizer.
Claim 16
Dependent Claim
68 words
A device as set forth in claim 1, including a shutter arranged in front of said photodetector, said shutter having a diaphragm aperture which is arranged at the focal point of a focusing optical system for the reflected part of the radiated light deflected by said polarizer, and is so dimensioned that the photodetector is shielded from interference or stray light from directions outside the transmitting solid angle.
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) | 1983-04-22 | 1983-10-22 | 1984-04-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1987-04-22 | 1987-10-22 | 1988-04-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1991-04-22 | 1991-10-22 | 1992-04-22 | $7700.00 | Window Closed / Lapsed |