Patent US3715685A successfully refreshed from Google Patents.
US3715685A
Expired / Lapsed
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High efficiency injection laser cavities
Assignee: AT&T Inc
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Filing: 1971-04-30
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Granted: 1973-02-06
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Expires: 1991-04-30
Abstract
Abstract The specification describes injection lasers employing heterosemiconductor structures for obtaining an enlarged crosssectional area cavity defined by an optical waveguide terminated by the cleaved faces of the semi-conductor structure (usually known as mirrors). The enlarged area of the cavity allows higher power output from the laser for the same power density on the mirrors. The power density is limited by damage to the mirrors. The waveguide produces an output consisting of two plane wave lobes for each mode. Techniques for mode enhancement are described from which higher ultimate power for a single mode and higher efficiency can e predicted without exciting modes of other order. Separation between the thresholds of competing modes can be enhanced, for example, by placing a spherical reflector in the path of one output lobe to focus the energy back into the original cavity while at the same time aperturing the mirror to block modes of other order. This expedient is based upon the uniqueness of the lobe angle for a given mode. Also described is a technique for combining the dual lobe output characteristic of this laser structure by using a beam splitter in reverse.
Inventors
- 👤 E Gordon
- 👤 D Maydan
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 21:27
CPC Classifications
H; H01; H01S; H01S5/00; H01S5/10; H01S5/14
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
112 words
An injection laser comprising: an active laser element; an optical waveguide enclosing said active element for confining the radiation generated in the active element; said laser element and said waveguide cooperating to produce a dual lobe divergent beam output in which the paths of the dual beams are symmetrical and acute with respect to the plane of the output reflector and in which each lobe is a uniphase, plane wave; and an optical beam combiner for combining the divergent beams from the laser into a single uniphase plane wave so that virtually all of the energy in the two lobes is brought stably into spatial and temporal coherence in the output beam.
Claim 2
Dependent Claim
112 words
An injection laser comprising: an active laser element; an optical waveguide enclosing said active element for confining the radiation generated in the active element; said laser element and said waveguide cooperating to produce a dual lobe divergent beam output in which the paths of the dual beams are symmetrical and acute with respect to the plane of the output reflector and in which each lobe is a uniphase, plane wave; and an optical beam combiner for combining the divergent beams from the laser into a single uniphase plane wave so that virtually all of the energy in the two lobes is brought stably into spatial and temporal coherence in the output beam.
Claim 3
Dependent Claim
112 words
An injection laser comprising: an active laser element; an optical waveguide enclosing said active element for confining the radiation generated in the active element; said laser element and said waveguide cooperating to produce a dual lobe divergent beam output in which the paths of the dual beams are symmetrical and acute with respect to the plane of the output reflector and in which each lobe is a uniphase, plane wave; and an optical beam combiner for combining the divergent beams from the laser into a single uniphase plane wave so that virtually all of the energy in the two lobes is brought stably into spatial and temporal coherence in the output beam.
Claim 4
Dependent Claim
112 words
An injection laser comprising: an active laser element; an optical waveguide enclosing said active element for confining the radiation generated in the active element; said laser element and said waveguide cooperating to produce a dual lobe divergent beam output in which the paths of the dual beams are symmetrical and acute with respect to the plane of the output reflector and in which each lobe is a uniphase, plane wave; and an optical beam combiner for combining the divergent beams from the laser into a single uniphase plane wave so that virtually all of the energy in the two lobes is brought stably into spatial and temporal coherence in the output beam.
Claim 5
Dependent Claim
16 words
The injection laser of claim 1 in which the optical beam combiner is a Kosters prism.
Claim 6
Dependent Claim
165 words
An injection laser comprising: an active laser element including a longitudinal cavity terminated at one end with an output reflector; an optical waveguide enclosing said active element for confining the radiation generated in the active element; said laser and waveguide cooperating to produce a dual lobe output in which the paths of the dual beams are symmetrical and acute with respect to the plane of the output deflector and in which each lobe is a uniphase, plane wave; and means for combining the dual lobes into a single uniphase output wave, said means comprising at least one spherical mirror disposed externally of the injection laser cavity in the far field to intersect one of the output lobes and spaced with the center of its curvature coincident with the output reflector of the injection laser so that radiation exiting in said one lobe from the cavity is efficiently reflected back into the cavity to enhance the intensity of the high order mode in the other lobe.
Claim 7
Dependent Claim
165 words
An injection laser comprising: an active laser element including a longitudinal cavity terminated at one end with an output reflector; an optical waveguide enclosing said active element for confining the radiation generated in the active element; said laser and waveguide cooperating to produce a dual lobe output in which the paths of the dual beams are symmetrical and acute with respect to the plane of the output deflector and in which each lobe is a uniphase, plane wave; and means for combining the dual lobes into a single uniphase output wave, said means comprising at least one spherical mirror disposed externally of the injection laser cavity in the far field to intersect one of the output lobes and spaced with the center of its curvature coincident with the output reflector of the injection laser so that radiation exiting in said one lobe from the cavity is efficiently reflected back into the cavity to enhance the intensity of the high order mode in the other lobe.
Claim 8
Dependent Claim
25 words
The laser of claim 3 further including means for aperturing the beam incident on the spherical mirror to eliminate unwanted modes from the injection laser.
Claim 9
Dependent Claim
37 words
The laser of claim 4 in which the aperture width lies in the range of Three-eighths to three-fourths the width of the lobe measured from first zero to first zero on either side of the main peak.
Claim 10
Dependent Claim
14 words
The laser of claim 4 in which the aperture is part of the reflector.
Claim 11
Dependent Claim
42 words
The laser of claim 4 in which the longitudinal cavity terminates at both ends with partially transparent reflectors and three apertured spherical reflectors are situated similarly to the aforesaid aperture means with respect to three output lobes from the injection laser cavity.
Claim 12
Dependent Claim
20 words
The laser of claim 4 in which the exit mirror of the longitudinal cavity is provided with an antireflection coating.
Claim 13
Dependent Claim
18 words
The laser of claim 4 in which the laser element and the optical waveguide comprise a heterosemiconductor structure.
Claim 14
Dependent Claim
31 words
The laser of claim 9 in which the heterosemiconductor comprises AlxGa(1 x)As:GaAs:GaAs:AlxGa(1 x)As where x in each case is sufficient to impart a significant refractive index discontinuity at the heterosemiconductor interface.
Claim 15
Dependent Claim
15 words
The laser of claim 10 in which the refractive index discontinuity is at least 0.01.
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) | 1976-02-06 | 1976-08-07 | 1977-02-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-02-06 | 1980-08-07 | 1981-02-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-02-06 | 1984-08-07 | 1985-02-06 | $7700.00 | Window Closed / Lapsed |