US4943133A
Expired / Lapsed
US
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Low loss semiconductor optical phase modulator
Assignee: Iconectiv LLC
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Filing: 1988-08-08
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Granted: 1990-07-24
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Expires: 2008-08-08
Abstract
Abstract A low loss optical waveguide modulator, an essential component of opto-electronic integrated circuits which can combine optical and electronic devices on a single chip optical communication systems is described. The modulator in our embodiment consists of a sequence of epitaxial layers on a single crystal substrate consisting of a n + -GaAs substrate, a n + -GaAs buffer layer, a n-Al 0 .05 Ga 0 .95 As electrode layer, an effective i-Al 0 .25 Ga 0 .75 As confinement layer, an i-GaAs guiding layer, an effective i-Al 0 .25 Ga 0 .75 As confinement layer, a p-Al 0 .25 Ga 0 .75 As electrode layer and a p + -GaAs cap layer. The layers have an index of refraction profile such that the index of refraction of the confinement layers are substantially less than the index of refraction of the guiding layer and the index of refraction of the first electrode layer is substantially greater than the index of refraction of the first confinement layer.
Inventors
- 👤 Robert J. Deri
- 👤 Elyahou Kapon
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 16:15
CPC Classifications
G; G02; G02F; G02F1/00; G02F1/01; G02F1/015; G02F1/025; G02F1/0151
Claims Analysis
Total Claims: 21
Claim 1
Independent Claim
91 words
A semiconductor waveguide modulator comprising a substrate having thereon sequential epitaxial layers all overlying one major surface of said substrate, said layers comprising, in the order named, a first electrode layer, a first confinement layer, a waveguiding layer, a second confinement layer and a second electrode layer wherein the indices of refraction of said first and second confinement layers are substantially lower than the index of refraction of said waveguiding layer and the index of refraction of said first electrode layer is substantially greater than that of the first confinement layer.
Claim 2
Dependent Claim
91 words
A semiconductor waveguide modulator comprising a substrate having thereon sequential epitaxial layers all overlying one major surface of said substrate, said layers comprising, in the order named, a first electrode layer, a first confinement layer, a waveguiding layer, a second confinement layer and a second electrode layer wherein the indices of refraction of said first and second confinement layers are substantially lower than the index of refraction of said waveguiding layer and the index of refraction of said first electrode layer is substantially greater than that of the first confinement layer.
Claim 3
Dependent Claim
23 words
The waveguide modulator of claim 1 further comprising a buffer layer on said substrate and over which said first electrode layer is formed.
Claim 4
Dependent Claim
27 words
The waveguide modulator of claim 1 wherein the E-field associated with the light propagating along the waveguide is confined so as not to overlap said electrode layers.
Claim 5
Dependent Claim
26 words
The waveguide modulator of claim 1 wherein said modulator is in a design selected from a p-i-n, Schottky barrier, carrier injection and quantum-well type device design.
Claim 6
Dependent Claim
13 words
The waveguide modulator of claim 1 wherein said modulator has a p-i-n structure.
Claim 7
Dependent Claim
19 words
The waveguide modulator of claim 1 further comprising electrical circuit elements integrated with said modulator on the same substrate.
Claim 8
Dependent Claim
20 words
The waveguide modulator of claim 1 having a loss of ≦1 dB/cm and an efficiency of at least 2 degrees/V-mm.
Claim 9
Dependent Claim
24 words
The waveguide modulator of claim 1 wherein said electrode layers are asymmetric in thickness and index of refraction with reference to said waveguiding layer.
Claim 10
Dependent Claim
110 words
A semiconductor waveguide modulator comprising a substrate having thereon sequential epitaxial layers comprising a first electrode layer, a first confinement layer, a waveguiding layer, a second confinement layer and a second electrode layer wherein the indices of refraction of said first and second confinement layers are substantially lower than the index of refraction of said waveguiding layer and the index of refraction of said first electrode layer is substantially greater than that of the first confinement layer, further comprising a semiconductor cap layer over said second electrode layer, said cap layer having a refractive index greater than that of said second electrode layer to provide a W-shaped refractive index profile.
Claim 11
Dependent Claim
110 words
A semiconductor waveguide modulator comprising a substrate having thereon sequential epitaxial layers comprising a first electrode layer, a first confinement layer, a waveguiding layer, a second confinement layer and a second electrode layer wherein the indices of refraction of said first and second confinement layers are substantially lower than the index of refraction of said waveguiding layer and the index of refraction of said first electrode layer is substantially greater than that of the first confinement layer, further comprising a semiconductor cap layer over said second electrode layer, said cap layer having a refractive index greater than that of said second electrode layer to provide a W-shaped refractive index profile.
Claim 12
Dependent Claim
91 words
A semiconductor waveguide modulator comprising a substrate having thereon sequential epitaxial layers comprising a first electrode layer, a first confinement layer, a waveguiding layer, a second confinement layer and a second electrode layer wherein the indices of refraction of said first and second confinement layers are substantially lower than the index of refraction of said waveguiding layer and the index of refraction of said first electrode layer is substantially greater than that of the first confinement layer, wherein at least one of said electrode and confinement layers is a superlattice heterostructure.
Claim 13
Dependent Claim
91 words
A semiconductor waveguide modulator comprising a substrate having thereon sequential epitaxial layers comprising a first electrode layer, a first confinement layer, a waveguiding layer, a second confinement layer and a second electrode layer wherein the indices of refraction of said first and second confinement layers are substantially lower than the index of refraction of said waveguiding layer and the index of refraction of said first electrode layer is substantially greater than that of the first confinement layer, wherein at least one of said electrode and confinement layers is a superlattice heterostructure.
Claim 14
Dependent Claim
149 words
A semiconductor waveguide modulator comprising a GaAs substrate having thereover sequential epitaxial layers comprising aluminum gallium arsenide and gallium arsenide including a first doped aluminum gallium arsenide electrode layer, a first effective intrinsic aluminum gallium arsenide confinement layer, an intrinsic gallium arsenide waveguide layer, a second effective intrinsic aluminum gallium arsenide confinement layer and a second doped aluminum gallium arsenide electrode layer wherein one of said electrode layers is doped with an n-type dopant, and the other with a p-type dopant, and wherein the index of refraction of the two confinement layers are significantly lower than the index of refraction of said waveguide layers and the index of refraction of said first electrode layer is higher than that of said first confinement layer, said layered structure being assymetric and wherein during operation the E-field of the guided wave is confined so as to essentially not overlap said electrode layers.
Claim 15
Dependent Claim
149 words
A semiconductor waveguide modulator comprising a GaAs substrate having thereover sequential epitaxial layers comprising aluminum gallium arsenide and gallium arsenide including a first doped aluminum gallium arsenide electrode layer, a first effective intrinsic aluminum gallium arsenide confinement layer, an intrinsic gallium arsenide waveguide layer, a second effective intrinsic aluminum gallium arsenide confinement layer and a second doped aluminum gallium arsenide electrode layer wherein one of said electrode layers is doped with an n-type dopant, and the other with a p-type dopant, and wherein the index of refraction of the two confinement layers are significantly lower than the index of refraction of said waveguide layers and the index of refraction of said first electrode layer is higher than that of said first confinement layer, said layered structure being assymetric and wherein during operation the E-field of the guided wave is confined so as to essentially not overlap said electrode layers.
Claim 16
Dependent Claim
25 words
The waveguide modulator recited in claim 11 wherein at least one of said electrode and confinement layers comprises a superlattice heterostructure including GaAs and AlGaAs.
Claim 17
Dependent Claim
22 words
The waveguide modulator recited in claim 12 wherein said superlattice has an effective composition of Al 0 .25 Ga 0 .75 As.
Claim 18
Dependent Claim
28 words
The waveguide modulator recited in claim 12 including an n + -GaAs buffer layer between said substrate and said first electrode layer, said first electrode layer being n-type.
Claim 19
Dependent Claim
19 words
The waveguide modulator recited in claim 14 including a p + -GaAs cap layer over said second electrode layer.
Claim 20
Dependent Claim
133 words
A semiconductor waveguide modulator integrated on a semiconductor device comprises a single crystal GaAs substrate, and sequential layers therein comprising a N + -GaAs buffer layer, an n-Al 0 .25 Ga 0 .75 As electrode layer, an effective i-Al 0 .25 Ga 0 .75 As first confinement layer, an i-GaAs waveguide layer, an effective i-Al 0 .25 Ga 0 .75 As second confinement layer, a p-Al 0 .25 Ga 0 .75 As second electrode layer and a p + -GaAs cap layer, the layer thicknesses being such that the E-field of light propagated along the waveguide is essentially confined to the region which includes the waveguide layer and surrounding confinement layers, said waveguide modulator having a loss at a wavelength of 1.5 μm of≦1 dB/cm and an efficiency of at least 2 degrees/V-mm.
Claim 21
Dependent Claim
133 words
A semiconductor waveguide modulator integrated on a semiconductor device comprises a single crystal GaAs substrate, and sequential layers therein comprising a N + -GaAs buffer layer, an n-Al 0 .25 Ga 0 .75 As electrode layer, an effective i-Al 0 .25 Ga 0 .75 As first confinement layer, an i-GaAs waveguide layer, an effective i-Al 0 .25 Ga 0 .75 As second confinement layer, a p-Al 0 .25 Ga 0 .75 As second electrode layer and a p + -GaAs cap layer, the layer thicknesses being such that the E-field of light propagated along the waveguide is essentially confined to the region which includes the waveguide layer and surrounding confinement layers, said waveguide modulator having a loss at a wavelength of 1.5 μm of≦1 dB/cm and an efficiency of at least 2 degrees/V-mm.
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