US5703357A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Methods for wavelength discrimination of monochromatic light beams
Assignee: Individual
•
Filing: 1994-09-22
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Granted: 1997-12-30
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Expires: 2014-09-22
Abstract
Abstract Methods for wavelength determination of a monochromatic beam are described. The methods involve a detector unit containing at least one variable filter and at least one pair of photo detectors. The detectors have photo sensitive regions with their areas varying with the position in one direction. The wavelength for maximum transmission of the variable filter varies in the same direction. By comparing the photo current values from the two detectors, wavelength of the incident beam is determined. Methods to construct wavelength discrimination junction photo detector pair and double barrier photo detector pair are also given.
Inventors
- 👤 Ishiang Shih
- 👤 Linh Ngo Phong
- 👤 Cindy Xing Qiu
- 👤 Philips Laou
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 21:06
CPC Classifications
G; G01; G01J; G01J3/00; G01J3/12; G01J3/26; G01J1/00; G01J1/02; G01J1/0204; G01J1/42; G01J1/4228; G01J9/00; H; H10; H10F; H10F30/00; H10F30/20; H10F30/21; H10F30/22; H10F30/227; H10F30/2275; H10F71/00; H10F71/121; H10F77/00; H10F77/10; H10F77/14; H10F77/148; H10F77/40; H10F77/413; H10F77/95; H10F77/953; H10F77/957; Y; Y02; Y02E; Y02E10/00; Y02E10/50; Y02E10/547; Y02P; Y02P70/00; Y02P70/50
Claims Analysis
Total Claims: 23
Claim 1
Independent Claim
161 words
A method for detection and wavelength discrimination of a monochromatic light beam comprising; installing at least one detector pair consisting of a first photo detector with progressively increasing active area per unit distance in one direction and a second photo detector aligned with the first, with progressively decreasing active area per unit distance in said direction, installing at least one variable filter on top of said detector pair, the maximum transmission wavelength of said variable filter varying with distance in said direction, measuring a first photo current generated in said first photo detector due to illumination of said monochromatic light beam through said variable filter, measuring a second photo current generated in said second photo detector due to illumination of said monochromatic light beam through said variable filter, comparing value of said first photo current and value of said second photo current, determining wavelength of said light beam from variation of maximum transmission wavelength of said variable filter in said direction.
Claim 2
Independent Claim
161 words
A method for detection and wavelength discrimination of a monochromatic light beam comprising; installing at least one detector pair consisting of a first photo detector with progressively increasing active area per unit distance in one direction and a second photo detector aligned with the first, with progressively decreasing active area per unit distance in said direction, installing at least one variable filter on top of said detector pair, the maximum transmission wavelength of said variable filter varying with distance in said direction, measuring a first photo current generated in said first photo detector due to illumination of said monochromatic light beam through said variable filter, measuring a second photo current generated in said second photo detector due to illumination of said monochromatic light beam through said variable filter, comparing value of said first photo current and value of said second photo current, determining wavelength of said light beam from variation of maximum transmission wavelength of said variable filter in said direction.
Claim 3
Dependent Claim
64 words
The method for detection and wavelength discrimination of a light beam as claimed in claim 1, further comprising the use of an amplifying means to amplify photo currents from said first detector and said second detector, an electrical filtering means to filter noises in said photo currents, and a trigger means to trigger sample and hold circuits to sample and hold said photo currents.
Claim 4
Dependent Claim
59 words
The method for detection and wavelength discrimination of a light beam as claimed in claim 1, wherein detection of said light beam is achieved by comparing said photo currents with a first threshold value; indication for the presence of said light beam being produced when at least one of said photo currents is greater than said first threshold value.
Claim 5
Dependent Claim
48 words
The method for detection and wavelength discrimination of a light beam as claimed in claim 1, wherein said first photo current is proportional to an integral of the active area of said first detector and transmission curve of said variable filter at the wavelength of said light beam.
Claim 6
Dependent Claim
48 words
The method for detection and wavelength discrimination of a light beam as claimed in claim 1, wherein said second photo current is proportional to an integral of the active area of said second detector and transmission curve of said variable filter at the wavelength of said light beam.
Claim 7
Dependent Claim
44 words
The method for detection and wavelength discrimination of a light beam as claimed in claim 1, wherein wavelength range of maximum transmission for said variable filter is not greater than photo response wavelength range of said first photo detector and said second photo detector.
Claim 8
Dependent Claim
32 words
The method for detection and wavelength discrimination of a light beam as claimed in claim 1, wherein said variable filter is located parallel and facing said active areas of said detector pair.
Claim 9
Dependent Claim
42 words
The method for detection and wavelength discrimination of a light beam as claimed in claim 1, further comprising a step of reducing separation between said active areas and multi layer coating of said variable filter to increase resolution of said wavelength discrimination.
Claim 10
Dependent Claim
25 words
The method for detection and wavelength discrimination of a light beam as claimed in claim 1, wherein said variable filter is a linear variable filter.
Claim 11
Dependent Claim
43 words
The method for detection and wavelength discrimination of a light beam as claimed in claim 1, wherein said photo detectors are selected from the group consisting of photoconductive detectors, photovoltaic detectors, double Schottky barrier detectors, p-i-n detectors, avalanche detectors and superconductor bolometric detectors.
Claim 12
Dependent Claim
88 words
The method for detection and wavelength discrimination of a light beam as claimed in claim 1 or 2 further comprising a step of using an electronic processor with a memory circuit, said memory circuit containing data for variation of maximum transmission wavelength with position of said variable filter, for measuring and comparing said photo currents, wherein the ratio of said photo currents is calculated and compared with the maximum transmission data stored in said memory to determine wavelength of said light beam and to produce an indication thereof.
Claim 13
Dependent Claim
56 words
The method for detection and wavelength discrimination of a light beam as claimed in claim 2, wherein an electrical signal to trigger said trigger means is supplied by a trigger detector, said trigger detector being installed near said detector pair and at least a part of said trigger detector is not covered by said variable filter.
Claim 14
Dependent Claim
31 words
The method for detection and wavelength discrimination of a light beam as claimed in claim 2, wherein an electrical signal to trigger said trigger means is supplied by said detector pair.
Claim 15
Independent Claim
128 words
A device for detection and wavelength discrimination of a monochromatic light beam comprising: at least one detection pair consisting of a photo detector with progressively increasing active area per unit distance in one direction and a second photo detector aligned with the first with progressively decreasing active area per unit distance in said direction; at least one variable filter on top of said detector pair, the maximum transmission wavelength of said variable filter varying with distance in said direction; means to measure and compare photo currents generated in said first and second photo detectors due to illumination of said monochromatic light beam through said variable filter; and means to determine the wavelength of said light beam from variation of maximum transmission of said variable filter in said direction.
Claim 16
Independent Claim
128 words
A device for detection and wavelength discrimination of a monochromatic light beam comprising: at least one detection pair consisting of a photo detector with progressively increasing active area per unit distance in one direction and a second photo detector aligned with the first with progressively decreasing active area per unit distance in said direction; at least one variable filter on top of said detector pair, the maximum transmission wavelength of said variable filter varying with distance in said direction; means to measure and compare photo currents generated in said first and second photo detectors due to illumination of said monochromatic light beam through said variable filter; and means to determine the wavelength of said light beam from variation of maximum transmission of said variable filter in said direction.
Claim 17
Dependent Claim
21 words
A device according to claim 14 wherein said variable filter is parallel and facing said active areas of said detector pair.
Claim 18
Dependent Claim
73 words
A device according to claim 14 further comprising an electronics processor with a memory circuit, said memory circuit containing data for variation of maximum transmission wavelength with position of said variable filter, for measuring and comparing said photo currents, wherein the ratio of said photo currents are calculated and compared with the maximum transmission data stored in said memory circuit to determine wavelength of said light beam and to produce an indication thereof.
Claim 19
Dependent Claim
15 words
A device according to claim 14 wherein said variable filter is a linear variable filter.
Claim 20
Dependent Claim
33 words
A device according to claim 14 wherein said photo detectors are selected from the group consisting of photoconductive detectors, photovoltaic detectors, double Schottky barrier detectors, p-i-n detectors, avalanche detectors and superconductor bolometric detectors.
Claim 21
Dependent Claim
51 words
A device according to claim 14 further comprising an amplifying means to amplify photo currents from said first detector and said second detector, an electrical filtering means to filter noises in said photo currents, and a trigger means to trigger sample and hold circuits to sample and hold said photo currents.
Claim 22
Dependent Claim
46 words
A device according to claim 19 wherein an electrical signal to trigger said trigger means is supplied by a trigger detector, the trigger detector being installed near the detector pair, with at least a part of said trigger detector not being covered by said variable filter.
Claim 23
Dependent Claim
21 words
A device according to claim 19 wherein an electrical signal to trigger said trigger means is supplied by said detector pair.
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| 7.5 Years (Year 8) | 2004-12-29 | 2005-06-30 | 2005-12-30 | $3760.00 | Window Closed / Lapsed |
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