US4573163A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Longitudinal mode stabilized laser
Assignee: Nokia Bell Labs
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Filing: 1982-09-13
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Granted: 1986-02-25
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Expires: 2002-09-13
Abstract
Abstract Stabilized, single-mode operation of semiconductor lasers is obtained by introducing longitudinally spaced variations in the effective refractive index along the active waveguiding medium, where said index changes have a spatial period corresponding to many half-wavelengths of the guided optic wave. Because the spatial period of the variations is relatively long, as opposed to half an optical wavelength used in the prior art distributed feedback lasers, a laser in accordance with the invention is much easier to fabricate.
Inventors
- 👤 Ivan P. Kaminow
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 11:39
CPC Classifications
H; H01; H01S; H01S5/00; H01S5/10; H01S5/1028; H01S5/12
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
34 words
A semiconductor laser comprising: an active medium; a first cladding layer of p-type semiconductor material; a second cladding layer of n-type medium semiconductor material, said active medium being between said first and second layers;
Claim 2
Dependent Claim
34 words
A semiconductor laser comprising: an active medium; a first cladding layer of p-type semiconductor material; a second cladding layer of n-type medium semiconductor material, said active medium being between said first and second layers;
Claim 3
Dependent Claim
63 words
first and second electrical contacts to said first and second layers, respectively; and a feedback mechanism including periodic perturbations in the transmission characteristic of said laser; characterized in that: the spatial period, Λ, of said perturbations is equal to at least ten times half the wavelength of the optical wave guided by said laser, said perturbations comprising refractive index changes of said laser.
Claim 4
Dependent Claim
63 words
first and second electrical contacts to said first and second layers, respectively; and a feedback mechanism including periodic perturbations in the transmission characteristic of said laser; characterized in that: the spatial period, Λ, of said perturbations is equal to at least ten times half the wavelength of the optical wave guided by said laser, said perturbations comprising refractive index changes of said laser.
Claim 5
Dependent Claim
42 words
The laser according to claim 1 wherein Λ=mλ/2N, where: λ is the free-space wavelength of the guided wave; N is the effective refractive index of the waveguide formed by said laser; and m is an integer equal to or greater than 10.
Claim 6
Dependent Claim
15 words
The laser according to claim 1 wherein said feedback mechanism is a Bragg diffraction grating.
Claim 7
Dependent Claim
19 words
The laser according to claim 1 wherein the feedback mechanism extends along the entire length, L, of said laser.
Claim 8
Dependent Claim
17 words
The laser according to claim 1 wherein the ends of said laser form a Fabry-Perot cavity resonator.
Claim 9
Dependent Claim
42 words
The laser according to claim 1 comprising an active layer of semiconductor material disposed between said first cladding layer and said second cladding layer; wherein at least one of said layers includes periodic discontinuities longitudinally distributed along the direction of wave propagation.
References Cited (Backward Citations)
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Cited
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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) | 1989-02-24 | 1989-08-26 | 1990-02-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1993-02-24 | 1993-08-26 | 1994-02-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1997-02-24 | 1997-08-26 | 1998-02-25 | $7700.00 | Window Closed / Lapsed |