US4731789A
Expired / Lapsed
US
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Clad superlattice semiconductor laser
Assignee: Xerox Corp
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Filing: 1985-05-13
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Granted: 1988-03-15
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Expires: 2005-05-13
Abstract
Abstract A clad superlattice semiconductor laser is fabricated utilizing Impurity Induced Disordering (IID) techniques that provides (1) reduction of free carrier absorption in the optical cavity and (2) the ability to selectively vary the amount of index guiding in the optical waveguide independent of the properties of the electron confining multiquantum well structure. The clad superlattice semiconductor laser provides for the novel inclusion of a superlattice in a cladding layer or region of the laser structure. An effective index waveguide can be realized by selectively disordering the cladding superlattice in regions adjacent to the formed index guide type optical cavity, as long as the superlattice is designed so that the established optical mode significantly overlaps with the disordered superlattice cladding regions, i.e., the evanescent wave propagating in the laser cavity overlaps into regions of the disordered superlattice.
Inventors
- 👤 Robert L. Thornton
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 01:18
CPC Classifications
H; H01; H01S; H01S5/00; H01S5/20; B; B82; B82Y; B82Y20/00; H01S5/2004; H01S5/2009; H01S5/2013; H01S5/2054; H01S5/2059; H01S5/30; H01S5/32; H01S5/3211; H01S5/3216; H01S5/34; H01S5/343; H01S5/34313; H01S5/3432
Claims Analysis
Total Claims: 22
Claim 1
Independent Claim
143 words
In a clad superlattice semiconductor laser comprising a plurality of planar semiconductor layers, one or more of said layers forming an active region for light wave generation and propagation under lasing conditions in a confined optical cavity which includes said active region, a cladding layer formed on opposite sides of said active region, a superlattice formed as part of at least one of said cladding layers and comprising alternating layers of wells and barriers, the improvement comprising a pair of spatially separated disordered regions formed in said superlattice along adjacent sides of said optical cavity via impurity induced disordering, the depth of said regions not extending into said active region, the disordering of said regions providing said regions with a resultant lower refractive index compared to the refractive index of said optical cavity region to form a refractive index waveguide in said laser.
Claim 2
Dependent Claim
143 words
In a clad superlattice semiconductor laser comprising a plurality of planar semiconductor layers, one or more of said layers forming an active region for light wave generation and propagation under lasing conditions in a confined optical cavity which includes said active region, a cladding layer formed on opposite sides of said active region, a superlattice formed as part of at least one of said cladding layers and comprising alternating layers of wells and barriers, the improvement comprising a pair of spatially separated disordered regions formed in said superlattice along adjacent sides of said optical cavity via impurity induced disordering, the depth of said regions not extending into said active region, the disordering of said regions providing said regions with a resultant lower refractive index compared to the refractive index of said optical cavity region to form a refractive index waveguide in said laser.
Claim 3
Dependent Claim
167 words
In a clad superlattice semiconductor laser comprising a plurality of planar semiconductor layers, one or more of said layers forming an active region for light wave generation and propagation under lasing conditions in a confined optical cavity which includes said active region, a cladding layer formed on opposite sides of said active region, a superlattice formed as part of at least one of said cladding layers and comprising alternating layers of wells and barriers, the improvement comprising a pair of spatially separated disordered regions formed in said superlattice along adjacent sides of said optical cavity via impurity induced disordering, the disordering of said regions providing said regions with a resultant lower refractive index compared to the refractive index of said optical cavity region to form a refractive index waveguide in said laser, and a cladding layer formed between said active region and said superlattice, the strength of optical coupling between said active region and said superlattice varied by altering the thickness and/or composition of said cladding layer.
Claim 4
Dependent Claim
167 words
In a clad superlattice semiconductor laser comprising a plurality of planar semiconductor layers, one or more of said layers forming an active region for light wave generation and propagation under lasing conditions in a confined optical cavity which includes said active region, a cladding layer formed on opposite sides of said active region, a superlattice formed as part of at least one of said cladding layers and comprising alternating layers of wells and barriers, the improvement comprising a pair of spatially separated disordered regions formed in said superlattice along adjacent sides of said optical cavity via impurity induced disordering, the disordering of said regions providing said regions with a resultant lower refractive index compared to the refractive index of said optical cavity region to form a refractive index waveguide in said laser, and a cladding layer formed between said active region and said superlattice, the strength of optical coupling between said active region and said superlattice varied by altering the thickness and/or composition of said cladding layer.
Claim 5
Dependent Claim
16 words
The clad superlattice semiconductor of claim 1 wherein said impurity induced disordering is accomplished by diffusion.
Claim 6
Dependent Claim
21 words
The clad superlattice semiconductor laser of claim 1 wherein said impurity induced disordering is accomplished by implant followed by an anneal.
Claim 7
Dependent Claim
17 words
The clad superlattice semiconductor laser of claim 1 wherein current confinement means is formed in said laser.
Claim 8
Dependent Claim
17 words
The clad superlattice semiconductor laser of claim 5 wherein said current confinement means comprises a proton implant.
Claim 9
Dependent Claim
31 words
The clad superlattice semiconductor laser of any one of claims 1, and 2 through 6 wherein said superlattice is formed between adjacent cladding layers on one side and said active region.
Claim 10
Dependent Claim
24 words
The clad superlattice semiconductor laser of any one of claims 1, and 2 through 6 wherein said active region is a single active layer.
Claim 11
Dependent Claim
24 words
The clad superlattice semiconductor laser of any one of claims 1, and 2 through 6 wherein said active region is a single quantum well.
Claim 12
Dependent Claim
24 words
The clad superlattice semiconductor laser of any one of claims 1, and 2 through 6 wherein said active region is a multiple quantum well.
Claim 13
Dependent Claim
96 words
The clad superlattice semiconductor laser of claim 1 wherein said laser includes two superlattices, each superlattice included as part of a cladding layer on opposite sides of said active region, a pair of spatially separated disordered regions formed in said superlattice along adjacent sides of said optical cavity via impurity induced disordering, the depth of said regions not extending into said active region, the disordering of said regions providing said regions with a resultant lower refractive index compared to the refractive index of said optical cavity region to form a refractive index waveguide in said laser.
Claim 14
Dependent Claim
48 words
The clad superlattice semiconductor laser of claim 11 wherein a cladding layer is formed between said active region and each of said superlattices, the strength of optical coupling between said active region and each of said superlattices varied by altering the thickness and composition of said cladding layers.
Claim 15
Dependent Claim
17 words
The clad superlattice semiconductor laser of claim 11 wherein said impurity induced disordering is accomplished by diffusion.
Claim 16
Dependent Claim
21 words
The clad superlattice semiconductor laser of claim 11 wherein said impurity induced disordering is accomplished by implant followed by an anneal.
Claim 17
Dependent Claim
17 words
The clad superlattice semiconductor laser of claim 11 wherein current confinement means is formed in said laser.
Claim 18
Dependent Claim
17 words
The clad superlattice semiconductor laser of claim 15 wherein said current confinement means comprises a proton implant.
Claim 19
Dependent Claim
29 words
The clad superlattice semiconductor laser of any one of claims 11 through 16 wherein said superlattice is formed between adjacent cladding layers on one side of said active region.
Claim 20
Dependent Claim
22 words
The clad superlattice semiconductor laser of any one of claims 11 through 16 wherein said active region is a single active layer.
Claim 21
Dependent Claim
22 words
The clad superlattice semiconductor laser of any one of claims 11 through 16 wherein said active region is a single quantum well.
Claim 22
Dependent Claim
22 words
The clad superlattice semiconductor laser of any one of claims 11 through 16 wherein said active region is a multiple quantum well.
References Cited (Backward Citations)
US4184171A
Cited
US4378255A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1991-03-15 | 1991-09-14 | 1992-03-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-03-15 | 1995-09-14 | 1996-03-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-03-15 | 1999-09-14 | 2000-03-15 | $7700.00 | Window Closed / Lapsed |