Patent US3723903A successfully refreshed from Google Patents.
US3723903A
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Dynamic fm control of the transverse modes of a self-pulsing semiconductor laser
Assignee: AT&T Inc
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Filing: 1971-05-13
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Granted: 1973-03-27
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Expires: 1991-05-13
Abstract
Abstract A semiconductor laser at appropriate values of current above threshold, enters a nonlinear regime characterized by (1) a continuous region in which the output radiation self-pulses simultaneously in two competing transverse modes and/or (2) a bistable region in which the output radiation self-pulses in either of two noncompeting transverse modes, but not both. A preselected one of these transverse modes is made to dominate by adding to the pump power a control signal at a frequency approximately equal to the pulsing frequency of the preselected mode. Alternatively, the laser is modulated (i.e., switched between different sets of modal families) by modulating the frequency of the control signal between two pulsing frequencies corresponding to different modal families.
Inventors
- 👤 T Paoli
- 👤 J Ripper
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 21:49
CPC Classifications
H; H01; H01S; H01S5/00; H01S5/06; H01S5/068; H01S5/0683
Claims Analysis
Total Claims: 16
Claim 1
Independent Claim
125 words
A method of controlling the transverse mode of distribution of a semiconductor laser comprising the steps of: applying to said laser pumping energy effective to induce in the optical output thereof self-pulsing in a nonlinear regime in which different transverse mode distributions may exist at different pulsing frequencies; applying to said laser a control signal having in at least some portion of its duration a frequency approximately equal to the pulsing frequency of a preselected one of said transverse mode distributions; and frequency-modulating said control signal over a range corresponding to the difference between said different pulsing frequencies, thereby causing said laser to switch between selfpulsing in one of said distributions to self-pulsing in another of said distributions in accordance with information to be transmitted.
Claim 2
Independent Claim
125 words
A method of controlling the transverse mode of distribution of a semiconductor laser comprising the steps of: applying to said laser pumping energy effective to induce in the optical output thereof self-pulsing in a nonlinear regime in which different transverse mode distributions may exist at different pulsing frequencies; applying to said laser a control signal having in at least some portion of its duration a frequency approximately equal to the pulsing frequency of a preselected one of said transverse mode distributions; and frequency-modulating said control signal over a range corresponding to the difference between said different pulsing frequencies, thereby causing said laser to switch between selfpulsing in one of said distributions to self-pulsing in another of said distributions in accordance with information to be transmitted.
Claim 3
Dependent Claim
34 words
The method of claim 1 wherein said pumping energy induces self-pulsing in a bistable region of said nonlinear regime in which either of said transverse mode distributions may exist separately, but not both simultaneously.
Claim 4
Dependent Claim
50 words
The method of claim 1 wherein said pumping energy induces self-pulsing in a continuous region of said nonlinear regime in which both of said transverse mode distributions exist simultaneously at a pulsing frequency intermediate the pulsing frequencies that said distributions would have if each were oscillating independent of the other.
Claim 5
Dependent Claim
13 words
The method of claim 1 wherein said laser comprises a p-n junction laser.
Claim 6
Dependent Claim
47 words
The method of claim 4 wherein said laser is switched between a first transverse mode distribution perpendicular to the plane of the junction of said laser to a second transverse mode distribution perpendicular to the junction plane of said laser in accordance with information to be transmitted.
Claim 7
Dependent Claim
14 words
The method of claim 4 wherein said laser comprises a double heterostructure junction laser.
Claim 8
Dependent Claim
26 words
The method of claim 6 wherein said laser comprises an AlGaAs double heterostructure junction laser and said pumping energy is provided by forward bias direct current.
Claim 9
Dependent Claim
118 words
Optical apparatus comprising: a semiconductor laser, pump means for applying pumping energy to said laser effective to induce therein self-pulsing in a nonlinear regime in which different transverse mode distributions may exist at different pulsing frequencies, control means for applying to said laser a control signal having in at least a portion of its duration a frequency approximately equal to the pulsing frequency of a preselected one of said transverse mode distributions, and means for frequency-modulating said control signal over a range corresponding to the difference between said different pulsing frequencies, thereby causing said laser to switch between self-pulsing in one of said distributions to self-pulsing in another of said distributions in accordance with information to be transmitted.
Claim 10
Dependent Claim
118 words
Optical apparatus comprising: a semiconductor laser, pump means for applying pumping energy to said laser effective to induce therein self-pulsing in a nonlinear regime in which different transverse mode distributions may exist at different pulsing frequencies, control means for applying to said laser a control signal having in at least a portion of its duration a frequency approximately equal to the pulsing frequency of a preselected one of said transverse mode distributions, and means for frequency-modulating said control signal over a range corresponding to the difference between said different pulsing frequencies, thereby causing said laser to switch between self-pulsing in one of said distributions to self-pulsing in another of said distributions in accordance with information to be transmitted.
Claim 11
Dependent Claim
34 words
The apparatus of claim 8 wherein said pump means induces self-pulsing in a bistable region of said nonlinear regime in which either of said transverse mode distributions may exist separately, but not both simultaneously.
Claim 12
Dependent Claim
50 words
The apparatus of claim 8 wherein said pump means induces self-pulsing in a continuous region of said nonlinear regime in which both of said transverse mode distributions exist simultaneously at a pulsing frequency intermediate the pulsing frequencies that said distributions would have if each were oscillating independent of the other.
Claim 13
Dependent Claim
13 words
The apparatus of claim 8 wherein said laser comprises a p-n junction laser.
Claim 14
Dependent Claim
47 words
The apparatus of claim 11 wherein said laser is switched between a first transverse mode distribution perpendicular to the plane of the junction of said laser to a second transverse mode distribution perpendicular to the junction plane of said laser in accordance with information to be transmitted.
Claim 15
Dependent Claim
14 words
The apparatus of claim 11 wherein said laser comprises a double heterostructure junction laser.
Claim 16
Dependent Claim
26 words
The apparatus of claim 13 wherein said laser comprises an AlGaAs double heterostructure junction laser and said pumping energy is provided by forward bias direct current.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-03-26 | 1976-09-25 | 1977-03-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-03-26 | 1980-09-25 | 1981-03-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-03-26 | 1984-09-25 | 1985-03-27 | $7700.00 | Window Closed / Lapsed |