Patent US5260822A successfully refreshed from Google Patents.
US5260822A
Expired / Lapsed
US
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Tapered semiconductor laser gain structure with cavity spoiling grooves
Assignee: Massachusetts Institute of Technology
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Filing: 1992-01-31
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Granted: 1993-11-09
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Expires: 2012-01-31
Abstract
Abstract A semiconductor laser gain structure having a tapered gain region comprising cavity spoilers for receiving light which is reflected off of the output facet back into the semiconductor and removing it from the gain region so as to reduce or eliminate self oscillation. The boundaries of the gain region are also designed to have a very low refractive index gradient so as to minimize reflection of light off of the boundaries back into the gain region. The gain structure may be embodied in a semiconductor laser oscillator or semiconductor laser amplifier depending on whether the input facet is or is not, respectively, anti reflection coated. The output facet is anti-reflection coated in either embodiment.
Inventors
- 👤 Leo J. Missaggia
- 👤 Christine A. Wang
- 👤 Stephen R. Chinn
- 👤 Emily S. Kintzer
- 👤 James N. Walpole
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 04:20
CPC Classifications
H; H01; H01S; H01S5/00; H01S5/50; H01S5/10; H01S5/1003; H01S5/1017; H01S5/1053; H01S5/1064; H01S5/12; H01S5/125
Claims Analysis
Total Claims: 28
Claim 1
Independent Claim
169 words
A semiconductor laser gain structure comprising: a section of semiconductor material having first and second interfaces at opposite ends thereof, a top surface, and a wave guiding layer in which layer electromagnetic radiation travels longitudinally between said first and second interfaces, an electrically conductive contact pad joined to said top surface of said semiconductor material and extending from said first interface to said second interface, said electrically conductive contact pad being tapered such that said pad is wider at said second interface than at said first interface, the portion of said wave guiding layer which is beneath said pad comprising a gain region of said layer, and cavity spoiling means in said wave guiding layer positioned outside of and adjacent said gain region so as to receive a portion the electromagnetic radiation which is reflected off of said second interface generally longitudinally back into said section of semiconductor material, said cavity spoiling means being adapted to remove said electromagnetic radiation which it receives from said section of semiconductor material.
Claim 2
Dependent Claim
169 words
A semiconductor laser gain structure comprising: a section of semiconductor material having first and second interfaces at opposite ends thereof, a top surface, and a wave guiding layer in which layer electromagnetic radiation travels longitudinally between said first and second interfaces, an electrically conductive contact pad joined to said top surface of said semiconductor material and extending from said first interface to said second interface, said electrically conductive contact pad being tapered such that said pad is wider at said second interface than at said first interface, the portion of said wave guiding layer which is beneath said pad comprising a gain region of said layer, and cavity spoiling means in said wave guiding layer positioned outside of and adjacent said gain region so as to receive a portion the electromagnetic radiation which is reflected off of said second interface generally longitudinally back into said section of semiconductor material, said cavity spoiling means being adapted to remove said electromagnetic radiation which it receives from said section of semiconductor material.
Claim 3
Dependent Claim
29 words
A semiconductor laser gain structure as set forth in claim 1 wherein said cavity spoiling means comprise two cavity spoiling means positioned on opposite sides of said gain region.
Claim 4
Dependent Claim
27 words
A semiconductor laser gain structure as set forth in claim 2 wherein said cavity spoiling means are positioned adjacent said first interface of said section of semiconductor.
Claim 5
Dependent Claim
19 words
A semiconductor laser gain structure as set forth in claim 3 wherein said cavity spoiling means comprises reflective surfaces.
Claim 6
Dependent Claim
40 words
A semiconductor laser gain structure as set forth in claim 4 wherein said cavity spoiling means comprise grooves etched into said wave guiding layer, said grooves defining said reflective surfaces which reflect said received light away from said gain region
Claim 7
Dependent Claim
28 words
A semiconductor laser gain structure as set forth in claim 2 wherein said cavity spoiling means comprise means for absorbing said light received by said cavity spoiling means
Claim 8
Dependent Claim
27 words
A semiconductor laser gain structure as set forth in claim 6 wherein said means for absorbing light comprise reverse biased junctions formed in said wave guiding layer.
Claim 9
Dependent Claim
28 words
A semiconductor laser gain structure as set forth in claim 6 wherein said cavity spoiling means extend substantially alongside said gain region between said first and second interfaces.
Claim 10
Dependent Claim
26 words
A semiconductor laser gain structure as set forth in claim 6 wherein said cavity spoiling means comprise ion implanted regions formed in said wave guiding layer.
Claim 11
Dependent Claim
29 words
A semiconductor laser gain structure as set forth in claim 9 wherein said ion implanted regions extend substantially alongside said gain region between said first and second end interfaces.
Claim 12
Dependent Claim
34 words
A semiconductor laser gain structure as set forth in claim 2 wherein said gain structure is a laser amplifier and said gain structure further comprises anti reflection coatings on said first and second interfaces.
Claim 13
Dependent Claim
54 words
A semiconductor laser gain structure as set forth in claim 2 wherein said electrically conductive contact pad is linearly tapered at a degree such that said gain region is large enough to allow electromagnetic radiation introduced at said first interface to expand in a substantially diffraction limited single lobed beam within said gain region.
Claim 14
Dependent Claim
36 words
A semiconductor laser gain structure as set forth in claim 4 wherein said reflective surface of said cavity spoiling means is positioned at a 14 degree angle from a plane parallel to said second end face.
Claim 15
Dependent Claim
27 words
A semiconductor laser gain structure as set said cavity spoiling means is positioned at a 45 degree angle from a plane parallel to said wave guiding layer.
Claim 16
Dependent Claim
27 words
A semiconductor laser gain structure as set said cavity spoiling means is positioned at a 45 degree angle from a plane parallel to said wave guiding layer.
Claim 17
Dependent Claim
33 words
A semiconductor laser gain structure as set forth in claim 14 wherein said wave guiding layer is adapted such that the refractive index gradient at the boundaries of said gain region is minimized.
Claim 18
Dependent Claim
33 words
A semiconductor laser gain structure as set forth in claim 1 wherein said wave guiding layer is adapted such that the refractive index gradient at the boundaries of said gain region is minimized.
Claim 19
Dependent Claim
32 words
A semiconductor laser gain structure as set forth in claim 15 wherein said section of semiconductor material further comprises first and second saw cut lateral faces connecting said first and second interfaces.
Claim 20
Dependent Claim
26 words
A semiconductor laser gain structure as set forth in claim 2 wherein said gain structure is a laser oscillator and said second interface is anti-reflection coated.
Claim 21
Dependent Claim
173 words
A semiconductor laser amplifier comprising: a section of semiconductor material having first and second interfaces at opposite ends thereof and a top surface, having a wave guiding layer in which light injected into said layer at said first interface travels longitudinally through said layer to said second interface, an electrically conductive contact pad joined to said top surface of said semiconductor material and extending from said first end interface to said second end interface, said electrically conductive contact pad being tapered such that said pad is wider at said second interface than at said first interface, the portion of said wave guiding layer which is beneath said pad comprising a gain region of said layer, and first and second cavity spoiling means in said wave guiding layer positioned adjacent and on opposite sides of said gain region so as to receive a portion of the electromagnetic radiation which is reflected off of said second interface generally longitudinally back into said section of semiconductor material and remove it from said section of semiconductor material.
Claim 22
Dependent Claim
173 words
A semiconductor laser amplifier comprising: a section of semiconductor material having first and second interfaces at opposite ends thereof and a top surface, having a wave guiding layer in which light injected into said layer at said first interface travels longitudinally through said layer to said second interface, an electrically conductive contact pad joined to said top surface of said semiconductor material and extending from said first end interface to said second end interface, said electrically conductive contact pad being tapered such that said pad is wider at said second interface than at said first interface, the portion of said wave guiding layer which is beneath said pad comprising a gain region of said layer, and first and second cavity spoiling means in said wave guiding layer positioned adjacent and on opposite sides of said gain region so as to receive a portion of the electromagnetic radiation which is reflected off of said second interface generally longitudinally back into said section of semiconductor material and remove it from said section of semiconductor material.
Claim 23
Dependent Claim
28 words
A semiconductor laser amplifier as set forth in claim 19 wherein said wave guiding layer is adapted such that the refractive index gradient across said layer is minimized.
Claim 24
Dependent Claim
49 words
A laser amplifier as set forth in claim 20 wherein said cavity spoiling means comprise grooves etched into said wave guiding layer adjacent said first interface, said voids defining reflective surfaces which reflect said light received off of said second interface and reflect it away from said gain region.
Claim 25
Dependent Claim
26 words
A laser amplifier as set forth in claim 20 wherein said cavity spoiling means comprise means for absorbing said light received by said cavity spoiling means.
Claim 26
Dependent Claim
35 words
A laser amplifier as set forth in claim 22 wherein said means for absorbing light comprise reverse biased junctions formed in said wave guiding layer for absorbing said light received by said cavity spoiling means.
Claim 27
Dependent Claim
27 words
A laser amplifier as set forth in claim 22 wherein said cavity spoiling means extend substantially alongside said gain region between said first and second end interfaces.
Claim 28
Dependent Claim
21 words
A semiconductor laser amplifier as set forth in claim 24 further comprising an anti-reflection coating on said first and second interfaces.
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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) | 1996-11-08 | 1997-05-10 | 1997-11-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2000-11-08 | 2001-05-10 | 2001-11-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2004-11-08 | 2005-05-10 | 2005-11-09 | $7700.00 | Window Closed / Lapsed |