US5428225A
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US
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Coupled quantum well optical intensity modulator for INP based optoelectronic integrated circuits and methods therefor
Assignee: Drexel University
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Filing: 1994-05-16
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Granted: 1995-06-27
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Expires: 2014-05-16
Abstract
Abstract An integrated optical intensity modulator. The modulator is an optical waveguide on a semi-insulating substrate and having a core layer for transmitting an optical signal. The modulator includes contiguous the core layer an active cladding which has a multicoupled quantum well structure. The multicoupled quantum well includes at least one pair of quantum wells separated by a barrier. The modulator further includes first and second additional claddings wherein the core layer and the active cladding are interposed between the additional claddings. A voltage source generates an electric field through the active cladding which varies the refractive index of the active cladding as a function of the strength of the electric field for modulating the optical signal.
Inventors
- 👤 Milson Silva
- 👤 Peter R. Herczfeld
- 👤 Steven A. Malone
- 👤 Arthur C. Paolella
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 05:13
CPC Classifications
G; G02; G02F; G02F1/00; G02F1/01; G02F1/015; G02F1/017; G02F1/01708; B; B82; B82Y; B82Y20/00; G02F1/0155; G02F1/0157; G02F1/01725; G02F1/01733; G02F2202/00; G02F2202/10; G02F2202/102
Claims Analysis
Total Claims: 25
Claim 1
Independent Claim
115 words
An integrated optical waveguide on a semi-insulating substrate for intensity modulating optical signals comprising: a core layer for transmitting an optical signal; an active cladding contiguous to the core layer, said active cladding including an optically coupled quantum well structure, said optically coupled quantum well structure including a pair of optically coupled quantum wells physically separated by a barrier; a first additional cladding; a second additional cladding, said core layer and said active cladding being interposed between the first and second additional claddings; and a voltage source for generating an electric field in the active cladding to vary the refractive index of the active cladding as a function of the strength of the electric field.
Claim 2
Dependent Claim
115 words
An integrated optical waveguide on a semi-insulating substrate for intensity modulating optical signals comprising: a core layer for transmitting an optical signal; an active cladding contiguous to the core layer, said active cladding including an optically coupled quantum well structure, said optically coupled quantum well structure including a pair of optically coupled quantum wells physically separated by a barrier; a first additional cladding; a second additional cladding, said core layer and said active cladding being interposed between the first and second additional claddings; and a voltage source for generating an electric field in the active cladding to vary the refractive index of the active cladding as a function of the strength of the electric field.
Claim 3
Dependent Claim
40 words
The waveguide of claim 1 further comprising a first cap layer and a second cap layer, said first cap layer being contiguous the substrate, said first and second additional claddings being interposed between the first and second cap layers, respectively.
Claim 4
Dependent Claim
46 words
The waveguide of claim 2 further comprising ohmic contacts provided by a periodic electrode pattern on the second cap layer and a ground electrode on the first cap layer, said voltage source being connected to the ohmic contacts for applying a reverse voltage to the waveguide.
Claim 5
Dependent Claim
20 words
The waveguide of claim 2 wherein the first cap layer comprises an n+ doped semiconductor layer formed on the substrate.
Claim 6
Dependent Claim
22 words
The waveguide of claim 2 wherein the second cap layer comprises a p+ doped semiconductor layer formed on the second additional cladding.
Claim 7
Dependent Claim
15 words
The waveguide of claim 2 wherein the cap layers are each approximately 1.0 μm thick.
Claim 8
Dependent Claim
13 words
The waveguide of claim 1 wherein the substrate comprises a substrate of InP.
Claim 9
Dependent Claim
15 words
The waveguide of claim 1 wherein the core layer comprises an n doped semiconductor layer.
Claim 10
Dependent Claim
14 words
The waveguide of claim 1 wherein the core layer comprises a layer of InGaAsP.
Claim 11
Dependent Claim
14 words
The waveguide of claim 1 wherein the core layer is approximately 0.34 μm thick.
Claim 12
Dependent Claim
14 words
The waveguide of claim 1 wherein each quantum well comprises a layer of InGaAsP.
Claim 13
Dependent Claim
14 words
The waveguide of claim 1 wherein each quantum well is approximately 35 Å thick.
Claim 14
Dependent Claim
13 words
The waveguide of claim 1 wherein the barrier comprises a layer of InP.
Claim 15
Dependent Claim
13 words
The waveguide of claim 1 wherein the barrier is approximately 30 Å thick.
Claim 16
Dependent Claim
43 words
The waveguide of claim 1 wherein the active cladding further comprises a second coupled quantum well structure contiguous the first said coupled quantum well structure, said second coupled quantum well structure including a second pair of quantum wells separated by a second barrier.
Claim 17
Dependent Claim
32 words
The waveguide of claim 15 wherein the active cladding further comprises a decoupling barrier for separating and decoupling the first said coupled quantum well structure from said second coupled quantum well structure.
Claim 18
Dependent Claim
16 words
The waveguide of claim 16 wherein the decoupling barrier comprises a 100 Å layer of InP.
Claim 19
Dependent Claim
14 words
The waveguide of claim 1 wherein the active cladding is approximately 0.1 μm thick.
Claim 20
Dependent Claim
16 words
The waveguide of claim 1 wherein the first additional cladding comprises an n doped semiconductor layer.
Claim 21
Dependent Claim
16 words
The waveguide of claim 1 wherein the second additional cladding comprises a p doped semiconductor layer.
Claim 22
Dependent Claim
167 words
An integrated optical waveguide on a semi-insulating substrate for intensity modulating optical signals comprising: a core layer for transmitting an optical signal; an active cladding contiguous to the core layer, said active cladding including a plurality of optically coupled quantum well structures, each optically coupled quantum well structure including a pair of optically coupled quantum wells physically separated by a barrier, each optically coupled quantum well structure being contiguous to another of the plurality of optically coupled quantum well structures and physically separated from the other of the optically coupled quantum well structures by a semi-insulating optically decoupling barrier for optically decoupling the optically coupled quantum well structures from each other; a first additional cladding; a second additional cladding, said core layer and said active cladding being interposed between the first and second additional claddings; and a voltage source for generating an electric field in the active cladding to vary the refractive index of the active cladding as a function of the strength of the electric field.
Claim 23
Dependent Claim
167 words
An integrated optical waveguide on a semi-insulating substrate for intensity modulating optical signals comprising: a core layer for transmitting an optical signal; an active cladding contiguous to the core layer, said active cladding including a plurality of optically coupled quantum well structures, each optically coupled quantum well structure including a pair of optically coupled quantum wells physically separated by a barrier, each optically coupled quantum well structure being contiguous to another of the plurality of optically coupled quantum well structures and physically separated from the other of the optically coupled quantum well structures by a semi-insulating optically decoupling barrier for optically decoupling the optically coupled quantum well structures from each other; a first additional cladding; a second additional cladding, said core layer and said active cladding being interposed between the first and second additional claddings; and a voltage source for generating an electric field in the active cladding to vary the refractive index of the active cladding as a function of the strength of the electric field.
Claim 24
Dependent Claim
129 words
An integrated optical waveguide on a semi-insulating substrate for intensity modulating optical signals comprising: an n+ doped cap layer formed on the substrate; an n doped cladding formed on the n+ doped cap layer; an n doped core layer formed on the n doped cladding for transmitting an optical signal; an active cladding including at least one pair of optically coupled quantum wells physically separated by a barrier, said active cladding being formed on the core layer; a p doped cladding formed on the active cladding; a p+ doped cap layer formed on the p doped cladding; and a voltage source for generating an electric field in the active cladding to vary the refractive index of the active cladding as a function of the strength of the electric field.
Claim 25
Dependent Claim
129 words
An integrated optical waveguide on a semi-insulating substrate for intensity modulating optical signals comprising: an n+ doped cap layer formed on the substrate; an n doped cladding formed on the n+ doped cap layer; an n doped core layer formed on the n doped cladding for transmitting an optical signal; an active cladding including at least one pair of optically coupled quantum wells physically separated by a barrier, said active cladding being formed on the core layer; a p doped cladding formed on the active cladding; a p+ doped cap layer formed on the p doped cladding; and a voltage source for generating an electric field in the active cladding to vary the refractive index of the active cladding as a function of the strength of the electric field.
References Cited (Backward Citations)
US5381023A
Cited
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| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
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| 3.5 Years (Year 4) | 1998-06-26 | 1998-12-26 | 1999-06-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2002-06-26 | 2002-12-26 | 2003-06-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2006-06-26 | 2006-12-26 | 2007-06-27 | $7700.00 | Window Closed / Lapsed |