US5824567A
Expired / Lapsed
US
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Methods for wavelength discrimination of monochromatic light beams
Assignee: Individual
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Filing: 1996-07-09
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Granted: 1998-10-20
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Expires: 2016-07-09
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 14:36
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: 18
Claim 1
Independent Claim
236 words
A method for fabrication at least one pair of a first junction photo detector and a second junction photo detector for detection and wavelength discrimination of a monochromatic light beam comprising the steps of: depositing a first electrically insulating layer over a front surface of a semiconductor substrate of one conduction type; removing selectively said first electrically insulating layer from at least a pair of polygon areas on surface of said semiconductor substrate; diffusing impurities into said polygon areas of semiconductor substrate to form active areas of another conduction type for said first and second junction photo detectors; depositing a second electrically insulating layer over said front surface; removing selectively said second electrically insulating layer from said polygon areas and at least a region on surface of said substrate; depositing a layer of ohmic contact metal over surface of said substrate and polygon areas; removing selectively said layer of ohmic metal to form at least an ohmic contact to said substrate and ohmic contacts each with fingers in said polygon areas, regions between adjacent fingers forming photo sensitive elements of said detectors, area per unit distance of said photo sensitive elements of said first detector increasing in one direction, while area per unit distance of said photo sensitive elements of said second detector decreases with distance in said direction; and attaching electrical wires to ohmic contact to said substrate and ohmic contacts to said polygon areas.
Claim 2
Independent Claim
236 words
A method for fabrication at least one pair of a first junction photo detector and a second junction photo detector for detection and wavelength discrimination of a monochromatic light beam comprising the steps of: depositing a first electrically insulating layer over a front surface of a semiconductor substrate of one conduction type; removing selectively said first electrically insulating layer from at least a pair of polygon areas on surface of said semiconductor substrate; diffusing impurities into said polygon areas of semiconductor substrate to form active areas of another conduction type for said first and second junction photo detectors; depositing a second electrically insulating layer over said front surface; removing selectively said second electrically insulating layer from said polygon areas and at least a region on surface of said substrate; depositing a layer of ohmic contact metal over surface of said substrate and polygon areas; removing selectively said layer of ohmic metal to form at least an ohmic contact to said substrate and ohmic contacts each with fingers in said polygon areas, regions between adjacent fingers forming photo sensitive elements of said detectors, area per unit distance of said photo sensitive elements of said first detector increasing in one direction, while area per unit distance of said photo sensitive elements of said second detector decreases with distance in said direction; and attaching electrical wires to ohmic contact to said substrate and ohmic contacts to said polygon areas.
Claim 3
Dependent Claim
103 words
A method for fabrication of junction photo detectors for detection and wavelength discrimination of a light beam as claimed in claim 1, wherein spacing between adjacent fingers is constant and the length of said fingers of the first detector in said pair increases in one direction, the length of said fingers of the second detector in said pair decreases in said direction, area per unit distance of photo sensitive active regions, between adjacent fingers, of said first detector increasing in said direction while area per unit distance of photo sensitive active regions of said second detector in said pair decreases in said direction.
Claim 4
Dependent Claim
96 words
A method for fabrication of junction photo detectors for detection and wavelength discrimination of a light beam as claimed in claim 1, wherein length of said fingers is constant and spacing between adjacent fingers in said first detector increases in one direction, spacing between said adjacent fingers of the second detector decreases in said direction, area per unit distance of photo sensitive active regions, between adjacent fingers, of said first detector increasing in said direction while area per unit distance of photo sensitive active regions of said second detector in said pair decreases in said direction.
Claim 5
Dependent Claim
107 words
A method for fabrication of junction photo detectors for detection and wavelength discrimination of a light beam as claimed in claim 1, wherein length of said fingers in said first detector increases in one direction, spacing between adjacent fingers also increases in said direction, length of said fingers in said second detector decreases in said direction while spacing between adjacent fingers also decreases in said direction, area per unit distance of photo sensitive active regions, between adjacent fingers, of said first detector increasing in said direction while area per unit distance of photo sensitive active regions of said second detector in said pair decreases in said direction.
Claim 6
Dependent Claim
39 words
A method for fabrication of junction photo detectors for detection and wavelength discrimination of a light beam as claimed in claim 1, further comprising a step of forming a trigger detector out side said polygon areas on said substrate.
Claim 7
Dependent Claim
63 words
A method for fabrication of junction photo detectors for detection and wavelength discrimination of a light beam as claimed in claim 1, further comprising a step of forming at least one semiconductor layer between said substrate and said diffused layer, said semiconductor layer having a resistivity at least 100 times greater than resistivity for said substrate to enhance generation of said photo current.
Claim 8
Dependent Claim
47 words
A method for fabrication of junction photo detectors for detection and wavelength discrimination of a light beam as claimed in claim 1, further comprising a step of depositing a variable filter on said substrate, the maximum wavelength of transmission of said variable filter varying in said direction.
Claim 9
Dependent Claim
53 words
A method for fabrication of junction photo detectors and variable filter for detection and wavelength discrimination of a light beam as claimed in claim 7, 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 10
Independent Claim
182 words
A method for fabrication of at least one pair of a first double barrier photo detector and a second double barrier photo detector for detection and wavelength discrimination of a light beam comprising the steps of: removing selectively a thin conducting semiconductor layer on a semiconductor substrate to form at least a pair of polygon areas for said first double barrier photo detector and said second double barrier photo detector, on front surface of said semiconductor layer; depositing a layer of metal over surface of said substrate and polygon areas, said layer of metal forms Schottky contacts to said thin conducting semiconductor layer; removing selectively said layer of metal to form at least one pair of contacts each with fingers in said polygon areas, regions between adjacent fingers form photo sensitive elements of said detectors, area per unit distance of said photo sensitive elements of said first detector increasing in one direction, while area per unit distance of said photo sensitive elements of said second detector decreases with distance in said direction; and attaching electrical wires to contacts of said polygon areas.
Claim 11
Independent Claim
182 words
A method for fabrication of at least one pair of a first double barrier photo detector and a second double barrier photo detector for detection and wavelength discrimination of a light beam comprising the steps of: removing selectively a thin conducting semiconductor layer on a semiconductor substrate to form at least a pair of polygon areas for said first double barrier photo detector and said second double barrier photo detector, on front surface of said semiconductor layer; depositing a layer of metal over surface of said substrate and polygon areas, said layer of metal forms Schottky contacts to said thin conducting semiconductor layer; removing selectively said layer of metal to form at least one pair of contacts each with fingers in said polygon areas, regions between adjacent fingers form photo sensitive elements of said detectors, area per unit distance of said photo sensitive elements of said first detector increasing in one direction, while area per unit distance of said photo sensitive elements of said second detector decreases with distance in said direction; and attaching electrical wires to contacts of said polygon areas.
Claim 12
Dependent Claim
102 words
A method for fabrication of double barrier photo detectors for detection and wavelength discrimination of a light beam as claimed in claim 9, wherein spacing between adjacent fingers is constant and length of said fingers of the first detector in said pair increases in one direction, length of said fingers of the second detector in said pair decreases in said direction, area per unit distance of photo sensitive active regions, between adjacent fingers, of said first detector increasing in said direction while area per unit distance of photo sensitive active regions of said second detector in said pair decreases in said direction.
Claim 13
Dependent Claim
100 words
A method for fabrication of double barrier photo detectors for detection and wavelength discrimination of a light beam as claimed in claim 9, wherein length of said fingers and spacing between adjacent fingers are constant, width of fingers in said first detector increases in one direction, while width of fingers of the second detector decreases in said direction, area per unit distance of photo sensitive active regions, defining by adjacent fingers, of said first detector decreasing in said direction while area per unit distance of photo sensitive active regions of said second detector in said pair increases in said direction.
Claim 14
Dependent Claim
108 words
A method for fabrication of double barrier photo detectors for detection and wavelength discrimination of a light beam as claimed in claim 9, wherein spacing between adjacent fingers are constant, length of said fingers decreases in one direction and width of said fingers increases in said first detector, while length of fingers increases in said direction, width of said fingers decreases in said second detector decreases, area per unit distance of photo sensitive active regions, defining by adjacent fingers, of said first detector decreasing in said direction while area per unit distance of photo sensitive active regions of said second detector in said pair increases in said direction.
Claim 15
Dependent Claim
37 words
A method for fabrication of double barrier photo detectors for detection and wavelength discrimination of a light beam as claimed in claim 9, further comprising a step of forming a trigger detector out side said polygon areas.
Claim 16
Dependent Claim
47 words
A method for fabrication of double barrier photo detectors for detection and wavelength discrimination of a light beam as claimed in claim 10, further comprising a step of depositing a variable filter on said substrate, maximum wavelength of transmission of said variable filter varies in said direction.
Claim 17
Dependent Claim
54 words
A method for fabrication of double barrier photo detectors and variable filter for detection and wavelength discrimination of a light beam as claimed in claim 14, 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 18
Dependent Claim
33 words
A method for fabrication of double barrier photo detectors for detection and wavelength discrimination of a light beam as claimed in claim 9, wherein said substrate semi insulating material has a high resistivity.
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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) | 2001-10-19 | 2002-04-20 | 2002-10-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2005-10-19 | 2006-04-20 | 2006-10-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2009-10-19 | 2010-04-20 | 2010-10-20 | $7700.00 | Window Closed / Lapsed |