US4843446A
Expired / Lapsed
US
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Superconducting photodetector
Assignee: Hitachi Ltd
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Filing: 1988-09-19
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Granted: 1989-06-27
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Expires: 2008-09-19
Abstract
Abstract A photodetector which operates at a cryogenic temperature by utilizing superconductivity is disclosed. A plurality of mutually spaced-apart superconducting layers are formed in such a manner as to be in contact with a semiconductor layer at least one of the surfaces of which is an incidence surface of light, and means capable of accumulating carriers in the semiconductor layer is disposed. A photodetector having high performance can thus be obtained and can be used as an interface of a system at a cryogenic temperature.
Inventors
- 👤 Toshikazu Nishino
- 👤 Ushio Kawabe
- 👤 Shinya Kominami
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 20:34
CPC Classifications
H; H10; H10F; H10F30/00; H10F30/20; H10F30/21; H10F30/28; H10F30/2823; H10N; H10N60/00; H10N60/10; H10N60/128
Claims Analysis
Total Claims: 25
Claim 1
Independent Claim
109 words
A superconducting photodetector comprising: a semiconductor substrate; at least two superconducting electrodes formed on a first surface of said semiconductor substrate spaced apart from one another wherein a superconducting weak coupling through said semiconductor substrate is formed between said spaced apart electrodes; an electrode means for accumulating a predetermined quantity of carriers in said semiconductor substrate between said superconducting electrodes to cause a critical superconducting current to flow between said superconducting electrodes; and means for radiating light to said semiconductor substrate between said superconducting electrodes so as to vary the number of carriers between said superconducting electrodes by excitation and to control superconducting current flowing between said superconducting electrodes.
Claim 2
Dependent Claim
109 words
A superconducting photodetector comprising: a semiconductor substrate; at least two superconducting electrodes formed on a first surface of said semiconductor substrate spaced apart from one another wherein a superconducting weak coupling through said semiconductor substrate is formed between said spaced apart electrodes; an electrode means for accumulating a predetermined quantity of carriers in said semiconductor substrate between said superconducting electrodes to cause a critical superconducting current to flow between said superconducting electrodes; and means for radiating light to said semiconductor substrate between said superconducting electrodes so as to vary the number of carriers between said superconducting electrodes by excitation and to control superconducting current flowing between said superconducting electrodes.
Claim 3
Dependent Claim
35 words
A superconducting photodetector according to claim 1, wherein said electrode means for accumulating carriers is a metal electrode disposed on said first surface of said semiconductor substrate through an insulating film between said superconducting electrodes.
Claim 4
Dependent Claim
30 words
A superconducting photodetector according to claim 1, wherein the impurity concentration of said semiconductor substrate is higher at portions where said semiconductor substrate comes into contact with said superconducting electrodes.
Claim 5
Dependent Claim
33 words
A superconducting photodetector according to claim 1, wherein said electrode means has a thickness such that light radiated by said radiating means acts as a signal and can transmit through said electrode means.
Claim 6
Dependent Claim
19 words
A superconducting photodetector according to claim 2, wherein said metal electrode consists of a film of Nb or NbN.
Claim 7
Dependent Claim
23 words
A superconducting photodetector according to claim 5, wherein said metal electrode is a Nb film having a thickness from 10 to 28 nm.
Claim 8
Dependent Claim
23 words
A superconducting photodetector according to claim 5, wherein said metal electrode is a NbN film having a thickness from 5 to 35 nm.
Claim 9
Dependent Claim
22 words
A superconducting photodetector according to claim 1, wherein said superconducting electrodes consist of films of at least one of Nb and NbN.
Claim 10
Dependent Claim
28 words
A superconducting photodetector according to claim 8, wherein said superconducting electrodes consist of a 10 to 28 nm-thick Nb film or a 5 to 35 nm-thick NbN film.
Claim 11
Dependent Claim
35 words
A superconducting photodetector according to claim 1, wherein said electrode means for accumulating carriers is a metal electrode formed through an insulation film on a second surface of said semiconductor substrate opposite said first surface.
Claim 12
Dependent Claim
32 words
A superconducting photodetector according to claim 1, wherein said electrode means for accumulating carriers is a light reflection layer formed on the opposite side to an incidence surface of said semiconductor substrate.
Claim 13
Dependent Claim
22 words
A superconducting photodetector according to claim 11, wherein an insulation film is disposed between said semiconductor substrate and said light reflection layer.
Claim 14
Dependent Claim
17 words
A superconducting photodetector according to claim 11, wherein said light reflection layer is made of a metal.
Claim 15
Dependent Claim
17 words
A superconducting photodetector according to claim 11, wherein said light reflection layer consists of a semiconductor layer.
Claim 16
Dependent Claim
18 words
A superconducting photodetector according to claim 1, wherein said semiconductor is made of two kinds of different semiconductors.
Claim 17
Dependent Claim
23 words
A semiconductor photodetector according to claim 1, wherein light is radiated by said radiating means to said first surface of said semiconductor substrate.
Claim 18
Dependent Claim
27 words
A semiconductor photodetector according to claim 1, wherein light is radiated by said radiating means to a second surface of said semiconductor substrate opposite said first surface.
Claim 19
Dependent Claim
23 words
A semiconductor photodetector according to claim 10, wherein light is radiated by said radiating means to said first surface of said semiconductor substrate.
Claim 20
Dependent Claim
23 words
A semiconductor photodetector according to claim 10, wherein light is radiated by said radiating means to said second surface of said semiconductor substrate.
Claim 21
Dependent Claim
32 words
A semiconductor photodetector according to claim 10, wherein said metal electrode has thickness such that light radiated by said radiating means acts as a signal and can transmit through said metal electrode.
Claim 22
Dependent Claim
19 words
A semiconductor photodetector according to claim 10, wherein said metal electrode consists of a film of Nb or NbN.
Claim 23
Dependent Claim
23 words
A semiconductor photodetector according to claim 21, wherein said metal electrode is a Nb film having a thickness from 10 to 28 nm.
Claim 24
Dependent Claim
23 words
A semiconductor photodetector according to claim 21, wherein said metal electrode is a NbN film having a thickness from 5 to 35 nm.
Claim 25
Dependent Claim
27 words
A semiconductor photodetector according to claim 1, wherein said superconducting electrodes are space apart a distance of 5 to 20 times the coherence length in said semiconductor.
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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) | 1992-06-26 | 1992-12-26 | 1993-06-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-06-26 | 1996-12-26 | 1997-06-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-06-26 | 2000-12-26 | 2001-06-27 | $7700.00 | Window Closed / Lapsed |