Patent US4958354A successfully refreshed from Google Patents.
US4958354A
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US
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Apparatus for stabilizing the intensity of light
Assignee: Hamamatsu Photonics KK
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Filing: 1989-05-08
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Granted: 1990-09-18
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Expires: 2009-05-08
Abstract
Abstract A light intensity stabilizing apparatus comprises an optical amplifier such as a non-resonant traveling-wave type optical amplifier, whose gain is adjustable by a controlling electrical signal and which amplifies incident light emitted from a light source, a beam splitting means for branching output light of the optical amplifier into stabilized output light and feedback light, a light intensity detector for converting said feedback light into an electrical signal, and a control unit for producing said controlling electrical signal in accordance with said electrical signal from said light intensity detector.
Inventors
- 👤 Tsuneyuki Urakami
- 👤 Shinichiro Aoshima
- 👤 Yutaka Tsuchiya
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 05:29
CPC Classifications
H; H01; H01S; H01S5/00; H01S5/06; H01S5/068; H01S5/0683; H01S5/50; H05; H05B; H05B47/00; H05B47/10
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
95 words
An apparatus for stabilizing intensity of light emitted from a light source to produce substantially constant-intensity light, comprising: an optical amplifier, having a gain which is adjustable by a controlling electrical signal, for amplifying incident light emitted from said light source; beam splitting means for branching said amplified incident light emitted from said light source into stabilized output light and feedback light; light intensity detecting means for converting said feedback light into an electrical signal; and control means for producing said control electrical signal in accordance with said electrical signal converted from said feedback light.
Claim 2
Independent Claim
95 words
An apparatus for stabilizing intensity of light emitted from a light source to produce substantially constant-intensity light, comprising: an optical amplifier, having a gain which is adjustable by a controlling electrical signal, for amplifying incident light emitted from said light source; beam splitting means for branching said amplified incident light emitted from said light source into stabilized output light and feedback light; light intensity detecting means for converting said feedback light into an electrical signal; and control means for producing said control electrical signal in accordance with said electrical signal converted from said feedback light.
Claim 3
Dependent Claim
38 words
An apparatus as claimed in claim 1, wherein said optical amplifier is a non-resonant traveling-wave type optical amplifier comprising a semiconductor laser and an anti-reflection film which is coated on each of end faces of said semiconductor laser.
Claim 4
Dependent Claim
35 words
An apparatus as claimed in claim 1, wherein said light intensity detecting means is a photodetector which is capable of high-speed response and produces said electrical signal corresponding to a waveform of said feedback light.
Claim 5
Dependent Claim
56 words
An apparatus as claimed in claim 1, wherein said control means comprises: a bias signal source for producing a reference dc signal; an amplifier for amplifying said electrical signal from said light intensity detecting means; a subtractor for producing said controlling electrical signal by subtracting an output signal of said amplifier from said reference dc signal.
Claim 6
Dependent Claim
73 words
An apparatus as claimed in claim 1, wherein said control means comprises: a waveform signal generator for producing a reference signal having a predetermined waveform; an amplifier for amplifying said electrical signal from said light intensity detecting means; a filter for cutting-off a dc component of an output signal of said amplifier; and a subtractor for producing said controlling electrical signal by subtracting an output signal of said filter from said reference signal.
References Cited (Backward Citations)
GB1073979A
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GB1535544A
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GB1511098A
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GB2048558A
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US4736164A
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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) | 1993-09-17 | 1994-03-19 | 1994-09-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-09-17 | 1998-03-19 | 1998-09-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-09-17 | 2002-03-19 | 2002-09-18 | $7700.00 | Window Closed / Lapsed |