US4933542A
Expired / Lapsed
US
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High speed photodetector having dual transmission line geometry
Assignee: Nokia Bell Labs
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Filing: 1988-10-31
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Granted: 1990-06-12
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Expires: 2008-10-31
Abstract
Abstract A vacuum photodetector has been fabricated in a coplanar microstrip transmission line geometry to achieve high quantum efficiency and picosecond response time. The coplanar microstrip transmission lines, photocathode and anode, are mounted on an insulating substrate such as sapphire and are electrically biased with respect to each other. Photodetection occurs by classical photoelectric emission as a result of impinging photon energies exceeding the work function of the photocathode.
Inventors
- 👤 Jeffrey Bokor
- 👤 Anthony M. Johnson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 02:54
CPC Classifications
G; G01; G01J; G01J11/00; G01J1/00; G01J1/42; H; H03; H03K; H03K17/00; H03K17/51; H03K17/78; H10; H10F; H10F30/00; H10F30/10
Claims Analysis
Total Claims: 17
Claim 1
Independent Claim
77 words
Photodetector for generating an electrical waveform in response to illumination by an optical signal, said photodetector including, a substrate comprising substantially insulating material, first and second conductive transmission lines mounted in substantially parallel, spaced-apart relationship on said substrate, means for contacting an electrical potential between said first and second conductive transmission lines, said first conductive transmission line responsive to illumination in a predetermined target region by said optical signal for generating said electrical waveform by photoelectric emission.
Claim 2
Dependent Claim
77 words
Photodetector for generating an electrical waveform in response to illumination by an optical signal, said photodetector including, a substrate comprising substantially insulating material, first and second conductive transmission lines mounted in substantially parallel, spaced-apart relationship on said substrate, means for contacting an electrical potential between said first and second conductive transmission lines, said first conductive transmission line responsive to illumination in a predetermined target region by said optical signal for generating said electrical waveform by photoelectric emission.
Claim 3
Dependent Claim
17 words
The photodetector defined in claim 1 wherein said first and second conductive transmission lines are substantially coplanar.
Claim 4
Dependent Claim
39 words
The photodetector defined in claim 2 wherein a said first and second conductive transmission lines comprise an electrically conductive material and said first conductive transmission line includes an layer at least at said predetermined target region comprising photocathode material.
Claim 5
Dependent Claim
15 words
The photodetector defined in claim 3 wherein said substrate includes a first layer comprising sapphire.
Claim 6
Dependent Claim
69 words
The photodetector defined in claim 1 wherein, at least in the vicinity of said predetermined target region, both said first conductive transmission line includes first and second sections being electrically isolated from each other and each of said first and second sections having one end formed as a plurality of spaced apart, interdigitated electrode fingers, alternate ones of said plurality of interdigitated electrode fingers extending from said first section.
Claim 7
Dependent Claim
17 words
The photodetector defined in claim 5 wherein said first and second conductive transmission lines are substantially coplanar.
Claim 8
Dependent Claim
39 words
The photodetector defined in claim 6 wherein a said first and second conductive transmission lines comprise an electrically conductive material and said first conductive transmission line includes an layer at least at said predetermined target region comprising photocathode material.
Claim 9
Dependent Claim
15 words
The photodetector defined in claim 7 wherein said substrate includes a first layer comprising sapphire.
Claim 10
Dependent Claim
22 words
The photodetector defined in claim 8 wherein adjacent ones of said interdigitated electrode fingers are equally spaced apart, one from the other.
Claim 11
Dependent Claim
36 words
The photodetector defined in claim 8 wherein adjacent ones of said interdigitated electrode fingers are equally spaced apart, one from the other, by a distance equal to the width of one of said interdigitated electrode fingers.
Claim 12
Dependent Claim
28 words
The photodetector defined in claim 9 wherein said photodetector further includes container means for enclosing at least said first and second conductive transmission lines in an evacuated atmosphere.
Claim 13
Dependent Claim
23 words
The photodetector defined in claim 11 wherein said evacuated atmosphere is maintained at a pressure less than or equal to 2×10 -6 torr.
Claim 14
Dependent Claim
28 words
The photodetector defined in claim 10 wherein said photodetector further includes container means for enclosing at least said first and second conductive transmission lines in an evacuated atmosphere.
Claim 15
Dependent Claim
23 words
The photodetector defined in claim 13 wherein said evacuated atmosphere is maintained at a pressure less than or equal to 2×10 -6 torr.
Claim 16
Dependent Claim
28 words
The photodetector defined in claim 4 wherein said photodetector further includes container means for enclosing at least said first and second conductive transmission lines in an evacuated atmosphere.
Claim 17
Dependent Claim
23 words
The photodetector defined in claim 15 wherein said evacuated atmosphere is maintained at a pressure less than or equal to 2×10 -6 torr.
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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) | 1993-06-11 | 1993-12-11 | 1994-06-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-06-11 | 1997-12-11 | 1998-06-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-06-11 | 2001-12-11 | 2002-06-12 | $7700.00 | Window Closed / Lapsed |