US5459799A
Expired / Lapsed
US
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Tunable optical filter
Assignee: Telefonaktiebolaget LM Ericsson AB
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Filing: 1994-08-12
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Granted: 1995-10-17
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Expires: 2014-08-12
Abstract
Abstract A tunable optical filter for use in wavelength division multiplexing systems. The optical filter contains a plurality of tunable reflection gratings which block all of the channels in the incoming lightwave. An electrode or a heating element is provided for each reflection grating to tune the reflection gratings so that their reflection bands do not coincide with a desired channel or channels thereby allowing the desired channel or channels to pass through the filter.
Inventors
- 👤 Jean-Pierre Weber
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 03:25
CPC Classifications
G; G02; G02F; G02F1/00; G02F1/01; G02F1/015; G02F1/025; G02F1/011; G02F1/0147; G02F2201/00; G02F2201/30; G02F2201/307; G02F2203/00; G02F2203/05; G02F2203/055; H; H01; H01S; H01S5/00; H01S5/10; H01S5/12; H01S5/1206; H01S5/1215; H01S5/50; H01S5/5045
Claims Analysis
Total Claims: 27
Claim 1
Independent Claim
114 words
A tunable optical filter, comprising: a first semiconductor substrate having a first electrode means provided on a first surface thereof; a waveguide means formed in and laterally defined within the surface of said substrate for carrying light waves; a plurality of tunable reflection grating means provided on a second surface of said semiconductor substrate on top of said waveguide, wherein said reflection grating blocks incoming lightwaves when said grating is untuned; an insulating substrate means provided on both sides of said waveguide; and a plurality of electrode means, wherein each of said tunable reflection gratings has an electrode for varying an effective index of refraction of a section of said waveguide below said grating.
Claim 2
Dependent Claim
114 words
A tunable optical filter, comprising: a first semiconductor substrate having a first electrode means provided on a first surface thereof; a waveguide means formed in and laterally defined within the surface of said substrate for carrying light waves; a plurality of tunable reflection grating means provided on a second surface of said semiconductor substrate on top of said waveguide, wherein said reflection grating blocks incoming lightwaves when said grating is untuned; an insulating substrate means provided on both sides of said waveguide; and a plurality of electrode means, wherein each of said tunable reflection gratings has an electrode for varying an effective index of refraction of a section of said waveguide below said grating.
Claim 3
Dependent Claim
17 words
A tunable optical filter according to claim 1, wherein each tunable reflection grating has a different period.
Claim 4
Dependent Claim
24 words
A tunable optical filter according to claim 1, wherein each channel of the incoming lightwave is blocked by one of the tunable reflection gratings.
Claim 5
Dependent Claim
23 words
A tunable optical filter according to claim 1, wherein said effective index of refraction is changed by free carrier injection in the waveguide.
Claim 6
Dependent Claim
23 words
A tunable optical filter according to claim 1, wherein said effective index of refraction is changed by free carrier depletion in the waveguide.
Claim 7
Dependent Claim
19 words
A tunable optical filter according to claim 1, wherein said effective index of refraction is changed by electro-optic tuning.
Claim 8
Dependent Claim
27 words
A tunable optical filter according to claim 1, wherein said gratings are such that all channels are blocked when no current is supplied to the corresponding electrode.
Claim 9
Dependent Claim
19 words
A tunable optical filter according to claim 1, wherein said effective index of refraction is changed by thermo-optic tuning.
Claim 10
Dependent Claim
24 words
A tunable optical filter according to claim 1, wherein said plurality of tunable reflection gratings block the entire wavelength range of an input signal.
Claim 11
Dependent Claim
30 words
A tunable optical filter according to claim 1, wherein said plurality of tunable reflection gratings have partially overlapping reflection bands to block the entire wavelength range of an input signal.
Claim 12
Dependent Claim
22 words
A tunable optical filter according to claim 1, wherein the reflection gratings block a plurality of channels from passing through said filter.
Claim 13
Dependent Claim
116 words
A tunable optical filter for a communication system with a plurality of channels, comprising: a first semiconductor substrate having a first electrode means provided on a first surface thereof; a waveguide means formed in and laterally defined within the surface of said substrate for carrying light waves; a plurality of tunable reflection gratings means provided on a second surface of said semiconductor substrate on top of said waveguide, wherein each of said tunable reflection gratings blocks a particular channel of the communication system; an insulating substrate means provided on both sides of said waveguides; and a plurality of electrode means for varying the effective index of refraction of a section of said waveguide below said grating.
Claim 14
Dependent Claim
116 words
A tunable optical filter for a communication system with a plurality of channels, comprising: a first semiconductor substrate having a first electrode means provided on a first surface thereof; a waveguide means formed in and laterally defined within the surface of said substrate for carrying light waves; a plurality of tunable reflection gratings means provided on a second surface of said semiconductor substrate on top of said waveguide, wherein each of said tunable reflection gratings blocks a particular channel of the communication system; an insulating substrate means provided on both sides of said waveguides; and a plurality of electrode means for varying the effective index of refraction of a section of said waveguide below said grating.
Claim 15
Dependent Claim
23 words
A tunable optical filter according to claim 12, wherein said effective index of refraction is changed by free carrier injection in the waveguide.
Claim 16
Dependent Claim
23 words
A tunable optical filter according to claim 12, wherein said effective index of refraction is changed by free carrier depletion in the waveguide.
Claim 17
Dependent Claim
19 words
A tunable optical filter according to claim 12, wherein said effective index of refraction is changed by electro-optic tuning.
Claim 18
Dependent Claim
22 words
A tunable optical filter according to claim 12, wherein said gratings block all channels when current is not supplied to said electrodes.
Claim 19
Dependent Claim
19 words
A tunable optical filter according to claim 12, wherein said effective index of refraction is changed by thermo-optic tuning.
Claim 20
Dependent Claim
96 words
A tunable optical filter, comprising: a substrate; a dielectric cladding layer provided on top of said substrate; a waveguide means formed in and laterally defined within the surface of said cladding layer; a plurality of tunable reflection grating means provided on top of said waveguide, wherein said reflection grating blocks incoming lightwaves when said grating is untuned; and a plurality of heating elements on top of said cladding layer, wherein each of said tunable reflection gratings has a heating element for varying an effective index of refraction of a section of said waveguide below said grating.
Claim 21
Dependent Claim
96 words
A tunable optical filter, comprising: a substrate; a dielectric cladding layer provided on top of said substrate; a waveguide means formed in and laterally defined within the surface of said cladding layer; a plurality of tunable reflection grating means provided on top of said waveguide, wherein said reflection grating blocks incoming lightwaves when said grating is untuned; and a plurality of heating elements on top of said cladding layer, wherein each of said tunable reflection gratings has a heating element for varying an effective index of refraction of a section of said waveguide below said grating.
Claim 22
Dependent Claim
17 words
A tunable optical filter according to claim 18, wherein each tunable reflection grating has a different period.
Claim 23
Dependent Claim
24 words
A tunable optical filter according to claim 18, wherein each channel of the incoming lightwave is blocked by one of the tunable reflection gratings.
Claim 24
Dependent Claim
19 words
A tunable optical filter according to claim 18, wherein said effective index of refraction is changed by thermo-optic tuning.
Claim 25
Dependent Claim
24 words
A tunable optical filter according to claim 18, wherein said plurality of tunable reflection gratings block the entire wavelength range of an input signal.
Claim 26
Dependent Claim
30 words
A tunable optical filter according to claim 18, wherein said plurality of tunable reflection gratings have partially overlapping reflection bands to block the entire wavelength range of an input signal.
Claim 27
Dependent Claim
22 words
A tunable optical filter according to claim 18, wherein the reflection gratings block a plurality of channels from passing through said filter.
References Cited (Backward Citations)
US4278327A
Cited
GB2170322A
Cited
US4826282A
Cited
EP0219069A2
Cited
US4837526A
Cited
US4885753A
Cited
US5035479A
Cited
US4923264A
Cited
US5155736A
Cited
US5073809A
Cited
GB2239100A
Cited
US5048907A
Cited
EP0496348A2
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) | 1998-10-16 | 1999-04-17 | 1999-10-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2002-10-16 | 2003-04-17 | 2003-10-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2006-10-16 | 2007-04-17 | 2007-10-17 | $7700.00 | Window Closed / Lapsed |