US5452318A
Expired / Lapsed
US
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Gain-coupled DFB laser with index coupling compensation
Assignee: Nortel Networks UK Ltd
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Filing: 1993-12-16
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Granted: 1995-09-19
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Expires: 2013-12-16
Abstract
Abstract A gain-coupled distributed feedback (DFB) laser or amplifier structure having a gain-coupling grating in the form of grooves periodically etched through strained, multi-quantum wells. The etched grooves are regrown with buffer material having a bandgap selected to compensate for index-coupling aid to block carrier leakage. The low carrier leakage reduces non-radiative recombination which in turn increases quantum efficiency.
Inventors
- 👤 Toshi Makino
- 👤 Guo P. Li
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 02:09
CPC Classifications
H; H01; H01S; H01S5/00; H01S5/10; H01S5/12; H01S5/1228; H01S5/18; H01S5/185; H01S5/187
Claims Analysis
Total Claims: 22
Claim 1
Independent Claim
140 words
A gain-coupled, distributed feedback (DFB), semi-conducting, lasing device comprising: a) a substrate; b) an active region on said substrate, said active region comprising material having a bandgap E g1 , said material capable of generating light and gain in response to a current therethrough; c) a gain coupling grating having periodic etched channels through said active region; d) a first regrown layer in said etched channels, said first regrown layer having a second bandgap E g2 , wherein E g2 >E g1 ; e) a second regrown layer on said first regrown layer said second regrown layer having a third bandgap E g3 ; wherein E g2 >E g3 >E g1 ; f) a current confining ridge on said active region and; g) contacts on said confining ridge and said substrate for use in injecting current into said active region.
Claim 2
Dependent Claim
140 words
A gain-coupled, distributed feedback (DFB), semi-conducting, lasing device comprising: a) a substrate; b) an active region on said substrate, said active region comprising material having a bandgap E g1 , said material capable of generating light and gain in response to a current therethrough; c) a gain coupling grating having periodic etched channels through said active region; d) a first regrown layer in said etched channels, said first regrown layer having a second bandgap E g2 , wherein E g2 >E g1 ; e) a second regrown layer on said first regrown layer said second regrown layer having a third bandgap E g3 ; wherein E g2 >E g3 >E g1 ; f) a current confining ridge on said active region and; g) contacts on said confining ridge and said substrate for use in injecting current into said active region.
Claim 3
Dependent Claim
26 words
A lasing device as defined in claim 1, said active region capable of generating light and gain for lasing action when the current therethrough exceeds threshold.
Claim 4
Dependent Claim
20 words
A lasing device as defined in claim 1, operating as an oscillating amplifier where the current therethrough is below threshold.
Claim 5
Dependent Claim
21 words
A lasing device as defined in claim 2, said active region including a plurality of quantum wells separated by quantum barriers.
Claim 6
Dependent Claim
17 words
A lasing device as defined in claim 2, said gain coupling grating being a first order grating.
Claim 7
Dependent Claim
22 words
A lasing device as defined in claim 5, wherein lasing action generates a laser beam which exits the edge of said device.
Claim 8
Dependent Claim
28 words
A lasing device as defined in claim 2, said active region being circular and surrounded by a second order grating which is surrounded by a first order grating.
Claim 9
Dependent Claim
19 words
A lasing device as defined in claim 6, the laser output being normal to the surface of said device.
Claim 10
Dependent Claim
30 words
A lasing device as defined in claim 1, the first and second regrown layers having the effect of diverting the current flow through said channels laterally through said quantum wells.
Claim 11
Dependent Claim
24 words
A lasing device as defined in claim 9, said second regrown layer having the effect of cancelling index coupling by said gain coupling grating.
Claim 12
Dependent Claim
16 words
A lasing device as defined in claim 2, said current confining ridge having a parallelpiped shape.
Claim 13
Dependent Claim
14 words
A lasing device as defined in claim 7, said current confining ridge being circular.
Claim 14
Dependent Claim
18 words
An amplifier as defined in claim 1, said substrate being N-type and said current confining ridge being P-type.
Claim 15
Dependent Claim
18 words
An amplifier as defined in claim 1, said substrate being P-type and said current confining ridge being N-type.
Claim 16
Dependent Claim
24 words
A lasing device as defined in claim 1, having the following bandgaps: E g1 =0.83 eV E g2 =1.35 eV E g3 =1 eV
Claim 17
Dependent Claim
12 words
A lasing device as defined in claim 1, said substrate being InP.
Claim 18
Dependent Claim
19 words
A lasing device as defined in claim 16, said generated light being in the wavelength range of 1.3-1.56 μm.
Claim 19
Dependent Claim
12 words
A lasing device as defined in claim 1, said substrate being GaAs.
Claim 20
Dependent Claim
19 words
A lasing device as defined in claim 18, said generated light being in the wavelength range of 0.8-0.9 μm.
Claim 21
Independent Claim
179 words
A method of fabricating a gain-coupled, distributed feedback (DFB) semi-conductor lasing device, said method comprising: a) epitaxially growing material capable of generating light and gain for optical amplification on a substrate, said material including a first cladding layer, a separate confinement layer, a plurality of quantum wells separated by quantum barriers and, a second separate confinement layer, said quantum wells having a first bandgap E g1 ; b) etching periodic grooves through said quantum wells; c) regrowing a first layer of a first material in said grooves, said first material having a second bandgap E g2 , wherein E g2 >E g1 ; d) regrowing a second layer of a second material on said first layer, said second layer having a third bandgap E g3 , wherein E g2 >E g3 >E g1 ; e) regrowing on said second layer a buffer layer, an etch stop layer, a second cladding layer and a capping layer, f) forming a current confining ridge in said capping layer and said cladding layer and; g) forming contacts on said ridge and said substrate.
Claim 22
Independent Claim
179 words
A method of fabricating a gain-coupled, distributed feedback (DFB) semi-conductor lasing device, said method comprising: a) epitaxially growing material capable of generating light and gain for optical amplification on a substrate, said material including a first cladding layer, a separate confinement layer, a plurality of quantum wells separated by quantum barriers and, a second separate confinement layer, said quantum wells having a first bandgap E g1 ; b) etching periodic grooves through said quantum wells; c) regrowing a first layer of a first material in said grooves, said first material having a second bandgap E g2 , wherein E g2 >E g1 ; d) regrowing a second layer of a second material on said first layer, said second layer having a third bandgap E g3 , wherein E g2 >E g3 >E g1 ; e) regrowing on said second layer a buffer layer, an etch stop layer, a second cladding layer and a capping layer, f) forming a current confining ridge in said capping layer and said cladding layer and; g) forming contacts on said ridge and said substrate.
References Cited (Backward Citations)
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| 7.5 Years (Year 8) | 2002-09-18 | 2003-03-20 | 2003-09-19 | $3760.00 | Window Closed / Lapsed |
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