Patent US5506925A successfully refreshed from Google Patents.
US5506925A
Expired / Lapsed
US
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Radiolytic modification of birefringence in silica planar waveguide structures
Assignee: AT&T Inc
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Filing: 1995-02-28
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Granted: 1996-04-09
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Expires: 2015-02-28
Abstract
Abstract A method for reducing birefringence in a silicate waveguide structure having a waveguide core and cladding includes the step of selecting an irradiation energy that induces compaction in the cladding. The waveguide structure is then irradiated with radiation having an energy equal to the irradiation energy to induce a reduction in birefringence.
Inventors
- 👤 Benjamin I. Greene
- 👤 Thomas A. Strasser
- 👤 Cynthia A. Volkert
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 04:30
CPC Classifications
C; C03; C03C; C03C25/00; C03C25/62; G; G02; G02B; G02B6/00; G02B6/10; G02B6/12; G02B6/126; G02B2006/12166
Claims Analysis
Total Claims: 38
Claim 1
Independent Claim
52 words
A method for reducing birefringence in a silicate waveguide structure having a waveguide core and cladding, said method comprising the step of: selecting an irradiation energy that induces compaction in the cladding; irradiating the waveguide structure with radiation having an energy equal to said irradiation energy to induce a reduction in birefringence.
Claim 2
Independent Claim
52 words
A method for reducing birefringence in a silicate waveguide structure having a waveguide core and cladding, said method comprising the step of: selecting an irradiation energy that induces compaction in the cladding; irradiating the waveguide structure with radiation having an energy equal to said irradiation energy to induce a reduction in birefringence.
Claim 3
Dependent Claim
28 words
The method of claim 1 wherein the energy selecting step comprises the step of selecting an irradiation energy sufficient to induce at least 0.1% compaction in the cladding.
Claim 4
Dependent Claim
28 words
The method of claim 1 wherein the energy selecting step comprises the step of selecting an irradiation energy sufficient to induce at least 0.1%-0.5% compaction in the cladding.
Claim 5
Dependent Claim
13 words
The method of claim 1 wherein said irradiation energy corresponds to ultraviolet radiation.
Claim 6
Dependent Claim
22 words
The method of claim 1 wherein said waveguide core is composed of phosphorous-doped silica and said irradiation energy corresponds to ultraviolet radiation.
Claim 7
Dependent Claim
15 words
The method of claim 5 wherein said irradiation energy has a wavelength of 193 nm.
Claim 8
Dependent Claim
24 words
The method of claim 1 wherein the step of irradiating the waveguide structure is performed for a period of time sufficient to eliminate birefringence.
Claim 9
Dependent Claim
26 words
The method of claim 2 wherein said irradiation energy is further selected to induce compaction in the core at a rate less than in the cladding.
Claim 10
Dependent Claim
15 words
The method of claim 4 wherein said radiation is provided by an excimer uv lamp.
Claim 11
Dependent Claim
14 words
The method of claim 1 further comprising the step of annealing said waveguide structure.
Claim 12
Dependent Claim
16 words
The method of claim 10 wherein the annealing step is performed simultaneous with the irradiation step.
Claim 13
Dependent Claim
16 words
The method of claim 10 wherein the annealing step is performed subsequent to the irradiation step.
Claim 14
Dependent Claim
45 words
The method of claim 1 further comprising the step of: overexposing the waveguide structure to the irradiation energy so that a change in sign of the birefringence is induced relative to its value prior to irradiation; annealing the waveguide structure until the birefringence is reduced.
Claim 15
Dependent Claim
16 words
The method of claim 13 wherein the annealing step is performed until the birefringence is eliminated.
Claim 16
Independent Claim
80 words
A method for reducing birefringence in a silicate waveguide structure having a waveguide core and cladding, said cladding having an optical absorption edge defining an energy range over which optical absorption increases exponentially, said method comprising the step of: selecting an irradiation energy above said energy range defined by said optical absorption edge of the waveguide cladding; irradiating the waveguide structure with ionized particles having an energy equal to said irradiation energy such that a reduction in birefringence is induced.
Claim 17
Independent Claim
80 words
A method for reducing birefringence in a silicate waveguide structure having a waveguide core and cladding, said cladding having an optical absorption edge defining an energy range over which optical absorption increases exponentially, said method comprising the step of: selecting an irradiation energy above said energy range defined by said optical absorption edge of the waveguide cladding; irradiating the waveguide structure with ionized particles having an energy equal to said irradiation energy such that a reduction in birefringence is induced.
Claim 18
Dependent Claim
10 words
The method of claim 15 wherein said particles comprise protons.
Claim 19
Dependent Claim
31 words
The method of claim 15 wherein said silicate waveguide structure has a core composed of phosphorous-doped silica and said radiation comprises protons having an energy at least equal to 1.5 Mev.
Claim 20
Dependent Claim
49 words
A silicate waveguide structure having a waveguide core and cladding, said structure fabricated by a method including the steps: selecting an irradiation energy that induces compaction in the cladding; irradiating the waveguide structure with radiation having an energy equal to said irradiation energy to induce a reduction in birefringence.
Claim 21
Dependent Claim
49 words
A silicate waveguide structure having a waveguide core and cladding, said structure fabricated by a method including the steps: selecting an irradiation energy that induces compaction in the cladding; irradiating the waveguide structure with radiation having an energy equal to said irradiation energy to induce a reduction in birefringence.
Claim 22
Dependent Claim
28 words
The structure of claim 18 wherein the energy selecting step comprises the step of selecting an irradiation energy sufficient to induce at least 0.1% compaction in the cladding.
Claim 23
Dependent Claim
28 words
The structure of claim 18 wherein the energy selecting step comprises the step of selecting an irradiation energy sufficient to induce at least 0.1%-0.5% compaction in the cladding.
Claim 24
Dependent Claim
13 words
The structure of claim 18 wherein said irradiation energy corresponds to ultraviolet radiation.
Claim 25
Dependent Claim
22 words
The structure of claim 18 wherein said waveguide core is composed of phosphorous-doped silica and said irradiation energy corresponds to ultraviolet radiation.
Claim 26
Dependent Claim
15 words
The structure of claim 22 wherein said irradiation energy has a wavelength of 193 nm.
Claim 27
Dependent Claim
24 words
The structure of claim 18 wherein the step of irradiating the waveguide structure is performed for a period of time sufficient to eliminate birefringence.
Claim 28
Dependent Claim
26 words
The structure of claim 19 wherein said irradiation energy is further selected to induce compaction in the core at a rate less than in the cladding.
Claim 29
Dependent Claim
30 words
The structure of claim 18 wherein said waveguide core and cladding are disposed on a silica substrate and further comprising the step of irradiating said waveguide structure through the substrate.
Claim 30
Dependent Claim
14 words
The structure of claim 18 further comprising the step of annealing said waveguide structure.
Claim 31
Dependent Claim
16 words
The structure of claim 27 wherein the annealing step is performed simultaneous with the irradiation step.
Claim 32
Dependent Claim
16 words
The structure of claim 27 wherein the annealing step is performed subsequent to the irradiation step.
Claim 33
Dependent Claim
45 words
The structure of claim 18 further comprising the step of: overexposing the waveguide structure to the irradiation energy so that a change in sign of the birefringence is induced relative to its value prior to irradiation; annealing the waveguide structure until the birefringence is reduced.
Claim 34
Dependent Claim
16 words
The structure of claim 30 wherein the annealing step is performed until the birefringence is eliminated.
Claim 35
Dependent Claim
78 words
A silicate waveguide structure having a waveguide core and cladding, said cladding having an optical absorption edge defining an energy range over which optical absorption increases exponentially, said structure fabricated by a method comprising the steps of: selecting an irradiation energy above said energy range defined by said optical absorption edge of the waveguide cladding; irradiating the waveguide structure with ionized particles having an energy equal to said irradiation energy such that a reduction in birefringence is induced.
Claim 36
Dependent Claim
78 words
A silicate waveguide structure having a waveguide core and cladding, said cladding having an optical absorption edge defining an energy range over which optical absorption increases exponentially, said structure fabricated by a method comprising the steps of: selecting an irradiation energy above said energy range defined by said optical absorption edge of the waveguide cladding; irradiating the waveguide structure with ionized particles having an energy equal to said irradiation energy such that a reduction in birefringence is induced.
Claim 37
Dependent Claim
10 words
The structure of claim 32 wherein said particles comprise protons.
Claim 38
Dependent Claim
31 words
The structure of claim 32 wherein said silicate waveguide structure has a core composed of phosphorous-doped silica and said radiation comprises protons having an energy at least equal to 1.5 Mev.
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