US3641459A
Expired / Lapsed
US
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Apparatus and method for narrowing the pulse width and stabilizing the repetition rate in semiconductor lasers exhibiting self-induced pulsing
Assignee: AT&T Inc
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Filing: 1969-12-01
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Granted: 1972-02-08
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Expires: 1989-12-01
Abstract
Abstract The width of pulses in the output of a semiconductor laser exhibiting self-induced pulsing is narrowed and its repetition rate stabilized by applying to the laser a perturbation signal having a frequency that is related to the pulse repetition rate as the ratio of two integral numbers.
Inventors
- 👤 Thomas L Paoli
- 👤 Jose E Ripper
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 10:29
CPC Classifications
H; H01; H01S; H01S5/00; H01S5/06; H01S5/062; H01S5/06209; H01S5/06216; H01S5/068; H01S5/0683; H01S5/06835; H04; H04B; H04B10/00; H04B10/50; H04B10/501; H04B10/503; H04B10/508; H01S3/00; H01S3/005; H01S3/0057; H01S5/065; H01S5/0658
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
83 words
A method for narrowing the pulse width and stabilizing the repetition rate in the output of a semiconductor laser exhibiting self-induced pulsing comprising the steps of: producing self-induced pulsing at a relative constant repetition rate in the output of a semiconductor laser; and applying to said laser a perturbation signal having a frequency related to the pulse repetition of said laser as the ratio of two integral numbers, said frequency determined automatically by the pulsing behavior of said laser through a feedback arrangement.
Claim 2
Independent Claim
83 words
A method for narrowing the pulse width and stabilizing the repetition rate in the output of a semiconductor laser exhibiting self-induced pulsing comprising the steps of: producing self-induced pulsing at a relative constant repetition rate in the output of a semiconductor laser; and applying to said laser a perturbation signal having a frequency related to the pulse repetition of said laser as the ratio of two integral numbers, said frequency determined automatically by the pulsing behavior of said laser through a feedback arrangement.
Claim 3
Dependent Claim
36 words
The method according to claim 1 wherein said perturbation signal is produced by amplifying the output of a photodiode receiving a portion of said laser output and applying the amplified output to the laser pumping source.
Claim 4
Dependent Claim
28 words
The method according to claim 1 whereIn said perturbation signal is a portion of the optical output of said laser applied to the active region of said laser.
Claim 5
Dependent Claim
53 words
The method according to claim 1 wherein: said semiconductor laser is a PN junction laser; said self-induced pulsing is produced by a DC voltage source; and the perturbation signal is applied to said laser by disposing it in a microwave cavity having a natural resonance frequency near the repetition rate of said laser.
Claim 6
Dependent Claim
53 words
The method according to claim 1 wherein said semiconductor laser is pumped by an injection current and wherein said perturbation signal is produced by amplifying the microwave energy produced by said laser at its repetition rate or a harmonic thereof, and feeding back said amplified energy into the injection current of said laser.
Claim 7
Dependent Claim
81 words
Optical apparatus comprising, in combination, a semiconductor laser; means for applying suitable pumping energy to said laser to produce self-induced pulsing at a relatively constant repetition rate; and means for applying to said laser a perturbation signal at a frequency related to the pulse repetition rate of said laser as the ratio of two integral numbers, said frequency determined automatically by the repetition rate of said laser, thereby to narrow the pulse width and stabilize the repetition rate of said pulses.
Claim 8
Dependent Claim
81 words
Optical apparatus comprising, in combination, a semiconductor laser; means for applying suitable pumping energy to said laser to produce self-induced pulsing at a relatively constant repetition rate; and means for applying to said laser a perturbation signal at a frequency related to the pulse repetition rate of said laser as the ratio of two integral numbers, said frequency determined automatically by the repetition rate of said laser, thereby to narrow the pulse width and stabilize the repetition rate of said pulses.
Claim 9
Dependent Claim
61 words
An optical pulse code modulation system having as a source of optical pulses apparatus according to claim 6 wherein: said means for applying a perturbation signal to said laser comprises a photodiode for receiving optical output from said laser and an amplifier coupled to the output of said photodiode for amplifying the photodiode signal and adding it to the pumping source.
Claim 10
Dependent Claim
35 words
Apparatus according to claim 6 wherein: said means for applying a perturbation signal to said laser comprises optical feedback means for applying a portion of the optical output to the active region of the laser.
Claim 11
Dependent Claim
31 words
Apparatus according to claim 6 wherein: said semiconductor laser is a PN junction laser; and, said means for applying a perturbation signal comprises an external microwave resonant cavity surrounding said laser.
Claim 12
Dependent Claim
53 words
Apparatus according to claim 6 wherein: said laser includes injection current pumping means, means for extracting microwave energy produced by said laser at its repetition rate or a harmonic thereof, means for amplifying said extracted microwave energy; and means for feeding back said amplified microwave energy into the injection current of said laser.
Claim 13
Dependent Claim
35 words
Apparatus according to claim 10 in combination with means included in said feedback means for varying the phase of said feed back microwave energy, thereby to pulse position modulate the pulsing output of said laser.
Claim 14
Dependent Claim
54 words
Apparatus according to claim 10 wherein: said pumping means comprise a DC source of voltage connected across opposite sides, said laser and an inductor connected in series with said source, said feedback means includes a three-port microwave circulator, said extracting means comprises capacitive coupling between said laser and one port of said circulator and
Claim 15
Dependent Claim
60 words
An optical pulse code modulating system comprising: an optical code modulator; and one or more light sources according to claim 6 disposed to pass light onto said modulator. said amplifying means comprises a microwave amplifier connected across the remaining two ports of said circulator such that signals amplified by said amplifier are coupled through said circulator to said one port.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-02-07 | 1975-08-09 | 1976-02-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-02-07 | 1979-08-09 | 1980-02-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-02-07 | 1983-08-09 | 1984-02-08 | $7700.00 | Window Closed / Lapsed |