Patent US5502787A successfully refreshed from Google Patents.
US5502787A
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US
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Article comprising a semiconductor waveguide structure
Assignee: AT&T Inc
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Filing: 1995-05-22
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Granted: 1996-03-26
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Expires: 2015-05-22
Abstract
Abstract Articles according to the invention include a semiconductor waveguide having a core and a cladding, with the cladding including doped semiconductor material. The doping level is selected such that both the real part n and the imaginary part k of the complex refractive index of the doped material are relatively low, exemplarily n<0.5 epsilon INFINITY 1/2 and k<1, where epsilon INFINITY is the high frequency lattice dielectric constant of the material. Appropriate choice of the doping level can result in improved confinement of the guided radiation without undue increase in the attenuation of the guided radiation. The invention exemplarily is embodied in a long wavelength ( DIFFERENCE 8.5 mu m) quantum cascade laser. Other embodiments are contemplated.
Inventors
- 👤 Federico Capasso
- 👤 Alfred Y. Cho
- 👤 Jerome Faist
- 👤 Albert L. Hutchinson
- 👤 Carlo Sirtori
- 👤 Deborah L. Sivco
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 21:41
CPC Classifications
G; G02; G02B; G02B6/00; G02B6/10; G02B6/12; G02B6/122; B; B82; B82Y; B82Y20/00; G02B6/1228; H; H01; H01S; H01S5/00; H01S5/20; H01S5/30; H01S5/305; H01S5/2004; H01S5/32; H01S5/3211; H01S5/34; H01S5/3401; H01S5/3402
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
103 words
An article comprising a semiconductor structure comprising a waveguide for radiation of vacuum wavelength λ, said waveguide comprising a core region and a cladding region having a refractive index that is less than a refractive index of the core region; CHARACTERIZED IN THAT said cladding region comprises doped semiconductor material having a dopant concentration N and a plasma radial frequency ω p , with N selected such that the doped semiconductor material has a complex refractive index that has a real part n <0.5 ε.sub.∞ 1/2 and an imaginary part k<1, where ε.sub.∞ is the high-frequency lattice dielectric constant of the semiconductor material.
Claim 2
Dependent Claim
103 words
An article comprising a semiconductor structure comprising a waveguide for radiation of vacuum wavelength λ, said waveguide comprising a core region and a cladding region having a refractive index that is less than a refractive index of the core region; CHARACTERIZED IN THAT said cladding region comprises doped semiconductor material having a dopant concentration N and a plasma radial frequency ω p , with N selected such that the doped semiconductor material has a complex refractive index that has a real part n <0.5 ε.sub.∞ 1/2 and an imaginary part k<1, where ε.sub.∞ is the high-frequency lattice dielectric constant of the semiconductor material.
Claim 3
Dependent Claim
23 words
Article according to claim 1, wherein said doped semiconductor material is doped n-type, with N selected such that n<0.25 ε.sub.∞ 1/2 and k<1.
Claim 4
Dependent Claim
8 words
Article according to claim 1, wherein λ>5 μm.
Claim 5
Dependent Claim
14 words
Article according to claim 1, wherein said doped semiconductor material is III/V semiconductor material.
Claim 6
Dependent Claim
12 words
Article according to claim 4, wherein the article is a semiconductor laser.
Claim 7
Dependent Claim
12 words
Article according to claim 1, wherein said doped semiconductor material comprises Si.
Claim 8
Dependent Claim
31 words
Article according to claim 6, wherein the article comprises a planar waveguide laterally defined by said doped semiconductor material and comprising a tapered core section that terminates at a core/air interface.
Claim 9
Dependent Claim
11 words
Article according to claim 1, wherein N>1×10 18 /cm 3 .
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) | 1999-03-26 | 1999-09-25 | 2000-03-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2003-03-26 | 2003-09-25 | 2004-03-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2007-03-26 | 2007-09-25 | 2008-03-26 | $7700.00 | Window Closed / Lapsed |