Patent US4941747A successfully refreshed from Google Patents.
US4941747A
Expired / Lapsed
US
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Optical sensing arrangements
Assignee: Siemens Plessey Controls Ltd
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Filing: 1989-02-10
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Granted: 1990-07-17
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Expires: 2009-02-10
Abstract
Abstract An optical scanning arrangement for gas sensing, in which scanned light source means produces a spectrum of regularly spaced wavelengths or lines which correspond as regards spacing to the absorption line spectrum of a gas to be monitored and in which the multi-line output from the light source means propagates through a region to be sensed for gas and means for determining the light output from the region for detecting the attenuation of the components of the multi-line output from the light source means due to absorption by said gas being monitored.
Inventors
- 👤 John P. Dakin
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 09:34
CPC Classifications
G; G01; G01N; G01N21/00; G01N21/17; G01N21/25; G01N21/31; G01N21/39; G01J; G01J3/00; G01J3/12; G01J3/26; G01N2201/00; G01N2201/06; G01N2201/062; G01N2201/0621; G01N2201/08; G01N2201/0826; G01N2201/084
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
104 words
An optical scanning arrangement for gas sensing, in which scanned light source means comprising a white or broadband light source and a frequency scanning comb filter produces a spectrum of regularly spaced wavelengths or lines which correspond as regards spacing to an absorption line spectrum or a gas to be monitored and in which a multi-line output from the light source means propagates through a region to be sensed for gas and means for determining the light output from the sensed region for detecting attenuation of components of the multi-line output from the light source means due to absorption by said gas being monitored.
Claim 2
Dependent Claim
104 words
An optical scanning arrangement for gas sensing, in which scanned light source means comprising a white or broadband light source and a frequency scanning comb filter produces a spectrum of regularly spaced wavelengths or lines which correspond as regards spacing to an absorption line spectrum or a gas to be monitored and in which a multi-line output from the light source means propagates through a region to be sensed for gas and means for determining the light output from the sensed region for detecting attenuation of components of the multi-line output from the light source means due to absorption by said gas being monitored.
Claim 3
Dependent Claim
19 words
An optical scanning arrangement as claimed in claim 1, in which the comb filter is of the Fabry-Perot type.
Claim 4
Dependent Claim
19 words
An optical scanning arrangement as claimed in claim 1, in which the comb filter comprises a guided Mach-Zehnder interferometer.
Claim 5
Dependent Claim
60 words
An optical scanning arrangement as claimed in claim 3, in which the light source means comprises a semiconductor device and the interferometer comprises two monomode branch paths of different predetermined lengths between which a monomode guided light signal in an input light path is divided, the two branched paths of the interferometer being recombined into a monomode output guide path.
Claim 6
Dependent Claim
20 words
An optically scanning arrangement as claimed in claim 4, in which the interferometer comprises a lithium niobate substrate intensity modulator.
Claim 7
Dependent Claim
23 words
An optical scanning arrangement as claimed in claim 1, in which the comb filter is provided by an integrated surface waveguide modulating arrangement.
References Cited (Backward Citations)
US4730112A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1993-07-16 | 1994-01-15 | 1994-07-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-07-16 | 1998-01-15 | 1998-07-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-07-16 | 2002-01-15 | 2002-07-17 | $7700.00 | Window Closed / Lapsed |