US3916182A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Periodic dielectric waveguide filter
Assignee: AT&T Inc
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Filing: 1973-08-03
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Granted: 1975-10-28
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Expires: 1993-08-03
Abstract
Abstract An optical waveguide comprising either a substrate coated with a layer of optic material or a clad optic fiber. A periodic variation in the index of refraction of either: (1) the substrate and/or the optical layer, or (2) the core and/or cladding of the optic fiber, is introduced so that unwanted frequency components present in the optical signal passing through the waveguide are eliminated. The waveguide may be employed as a band-pass or a band-stop filter, or for phase-matching purposes. Various means are disclosed for altering the periodicity of the index of refraction to thereby tune the device.
Inventors
- 👤 Franklin Winston Dabby
- 👤 Ami Kestenbaum
- 👤 Un-Chul Paek
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 08:57
CPC Classifications
G; G02; G02B; G02B6/00; G02B6/02; G02B6/02295; G02B6/023; G02B6/02057; G02B6/02076; G02B6/0208; G02B6/021; G02B6/10; G02B6/12; G02B6/122; G02B6/124; G02B6/14; G02B6/24; G02B6/26; G02B6/28; G02B6/293; G02B6/29304; G02B6/29316; G02B6/29325; G02B6/29329; G02F; G02F1/00; G02F1/01; G02F1/011; G02F1/11; G02F1/125; H; H04; H04B; H04B10/00; G02F1/0126; G02F1/35; G02F1/353; G02F1/3544; G02F1/3548; G02F2203/00; G02F2203/05; G02F2203/055; G02F2203/22
Claims Analysis
Total Claims: 56
Claim 1
Independent Claim
103 words
A device for selectively filtering light transmitted through an optical waveguide having a substrate element and an overlying layer element, characterizd by a region of one of the elements having a periodic, spatial variation in the index of refraction along the propagation axis of the waveguide, the period d of said variation being less than lambda /(nep - ns), where lambda is the free-space wavelength of at least one of the components of the light propagating through the waveguide, nep is the effective index of refraction in the guide of the component, and ns is the index of refraction of the substrate element.
Claim 2
Independent Claim
103 words
A device for selectively filtering light transmitted through an optical waveguide having a substrate element and an overlying layer element, characterizd by a region of one of the elements having a periodic, spatial variation in the index of refraction along the propagation axis of the waveguide, the period d of said variation being less than lambda /(nep - ns), where lambda is the free-space wavelength of at least one of the components of the light propagating through the waveguide, nep is the effective index of refraction in the guide of the component, and ns is the index of refraction of the substrate element.
Claim 3
Dependent Claim
23 words
The device according to claim 1 wherein said periodic variation is a sinusoidal variation in the optical dielectric constant according to the equation:
Claim 4
Dependent Claim
12 words
The device according to claim 1 wherein said periodic variation is non-sinusoidal.
Claim 5
Dependent Claim
24 words
The device according to claim 1 further comprising means for altering the periodicity of the variation in the index of refraction in said region.
Claim 6
Dependent Claim
110 words
Apparatus for filtering optical energy, which comprises: a substrate having a first uniform index of refraction; a layer of optical material overlaid on said substrate, said material exhibiting the property that the index of refraction thereof may be altered by the application of radiant energy thereto; and means for supplying first and second temporally coherent sources of optical energy to said layer, said first and second sources impinging upon said layer to create an interference pattern on the surface thereof, said interference pattern causing a corresponding periodic variation in the index of refraction of said optical layer, whereby said optical layer and said substrate function as a band-pass optical filter.
Claim 7
Dependent Claim
110 words
Apparatus for filtering optical energy, which comprises: a substrate having a first uniform index of refraction; a layer of optical material overlaid on said substrate, said material exhibiting the property that the index of refraction thereof may be altered by the application of radiant energy thereto; and means for supplying first and second temporally coherent sources of optical energy to said layer, said first and second sources impinging upon said layer to create an interference pattern on the surface thereof, said interference pattern causing a corresponding periodic variation in the index of refraction of said optical layer, whereby said optical layer and said substrate function as a band-pass optical filter.
Claim 8
Dependent Claim
71 words
Apparatus for filtering optical energy, which comprises: a substrate having a first, uniform index of refraction; a layer of light-conducting material overlaid on said substrate, said layer having a second index of refraction which is greater than the index of refraction of said substrate; and means for establishing an acoustical standing wave in said layer, said standing wave inducing a corresponding periodic change in the index of refraction of said layer.
Claim 9
Dependent Claim
71 words
Apparatus for filtering optical energy, which comprises: a substrate having a first, uniform index of refraction; a layer of light-conducting material overlaid on said substrate, said layer having a second index of refraction which is greater than the index of refraction of said substrate; and means for establishing an acoustical standing wave in said layer, said standing wave inducing a corresponding periodic change in the index of refraction of said layer.
Claim 10
Dependent Claim
32 words
The apparatus according to claim 6 wherein said establishing means comprises a transducer positioned proximate one end of said layer; and means for supplying a source of alternating current to said transducer.
Claim 11
Dependent Claim
13 words
The apparatus according to claim 7 wherein said transducer includes a piezo-electrical crystal.
Claim 12
Dependent Claim
108 words
Apparatus for filtering optical energy, which comprises: a band-pass, optical filter comprising: a substrate having a first, uniform index of refraction; and a layer of light-conducting material overlaid on said substrate, said layer having a periodically varying index of refraction in the direction of propagation of said filter; means for applying optical energy to said optical filter; means for dissipating optical energy escaping from said band-pass filter, said escaping energy having a wavelength less than the minimum wavelength of propagation in said filter; and a utilization device positioned proximate the output of said filter for receiving the energy from said source which succeeds in passing through said filter.
Claim 13
Dependent Claim
108 words
Apparatus for filtering optical energy, which comprises: a band-pass, optical filter comprising: a substrate having a first, uniform index of refraction; and a layer of light-conducting material overlaid on said substrate, said layer having a periodically varying index of refraction in the direction of propagation of said filter; means for applying optical energy to said optical filter; means for dissipating optical energy escaping from said band-pass filter, said escaping energy having a wavelength less than the minimum wavelength of propagation in said filter; and a utilization device positioned proximate the output of said filter for receiving the energy from said source which succeeds in passing through said filter.
Claim 14
Dependent Claim
96 words
An optical waveguide for transmitting optical information from a first location to a second location, comprising: a substrate having a first index of refraction which varies periodically along the direction of propagation of the waveguide; and a layer of light-conducting material overlaid on said substrate, said layer having a second, uniform index of refracton, the index variation in the substrate existing therein for at least that portion thereof in contact with said layer, whereby unwanted frequency components present in, or developed during the propagation of said optical information as it travels along said waveguide, are suppressed.
Claim 15
Dependent Claim
96 words
An optical waveguide for transmitting optical information from a first location to a second location, comprising: a substrate having a first index of refraction which varies periodically along the direction of propagation of the waveguide; and a layer of light-conducting material overlaid on said substrate, said layer having a second, uniform index of refracton, the index variation in the substrate existing therein for at least that portion thereof in contact with said layer, whereby unwanted frequency components present in, or developed during the propagation of said optical information as it travels along said waveguide, are suppressed.
Claim 16
Dependent Claim
24 words
The optical waveguide according to claim 10 wherein said periodic variation is a sinusoidal variation in the optical dielectric constant, according to the equation:
Claim 17
Dependent Claim
13 words
The optical waveguide according to claim 10 wherein said periodic variation is non-sinusoidal.
Claim 18
Dependent Claim
23 words
The optical waveguide according to claim 10 further comprising means for varying the periodicity of said periodic variation in said index of refraction.
Claim 19
Dependent Claim
71 words
Apparatus for filtering optical energy, which comprises: a substrate having a first index of refraction; an layer of light-conducting material overlaid on said substrate, said optical layer having a second index of refraction which is greater than the index of refraction of said substrate; and means for establishing an acoustical standing wave in said substrate, said standing wave inducing a corresponding periodic change in the index of refraction of said substrate.
Claim 20
Dependent Claim
71 words
Apparatus for filtering optical energy, which comprises: a substrate having a first index of refraction; an layer of light-conducting material overlaid on said substrate, said optical layer having a second index of refraction which is greater than the index of refraction of said substrate; and means for establishing an acoustical standing wave in said substrate, said standing wave inducing a corresponding periodic change in the index of refraction of said substrate.
Claim 21
Dependent Claim
32 words
The apparatus according to claim 14 wherein said establishing means comprises a transducer positioned proximate one end of said substrate; and means for supplying a source of alternating current to said transducer.
Claim 22
Dependent Claim
13 words
The apparatus according to claim 15 wherein said transducer includes a piezo-electrical crystal.
Claim 23
Dependent Claim
64 words
An optical transmission system, which comprises: an optical waveguide comprising a substrate and at least one layer of light-conducting material overlaid thereon, at least one of the components of said waveguide having a periodic variation in the index of refraction thereof; means for introducing modulated optical information into one end of said waveguide; and an optical demodulator proximate the other end of said waveguide.
Claim 24
Dependent Claim
64 words
An optical transmission system, which comprises: an optical waveguide comprising a substrate and at least one layer of light-conducting material overlaid thereon, at least one of the components of said waveguide having a periodic variation in the index of refraction thereof; means for introducing modulated optical information into one end of said waveguide; and an optical demodulator proximate the other end of said waveguide.
Claim 25
Dependent Claim
31 words
The optical transmission system according to claim 17 further comprising: at least one amplifying means, positioned intermediate the ends of said waveguide, for amplifying the optical information traveling in said waveguide.
Claim 26
Dependent Claim
31 words
The optical transmission system according to claim 17 wherein said introducing means comprises: an optical maser; and an optical modulator positioned intermediate the optical maser and the end of said waveguide.
Claim 27
Dependent Claim
79 words
An optical band-pass filter having a high attenuation for optical signals having frequencies above an upper predetermined limit and below a lower predetermined limit, and low attenuation for signals having optical frequencies lying between said upper and lower limits, which comprises: a substrate having a first, uniform index of refraction; and a layer of light-conducting material overlaid on said substrate, said layer having a second index of refraction which varies periodically along the direction of propagation of said filter.
Claim 28
Dependent Claim
79 words
An optical band-pass filter having a high attenuation for optical signals having frequencies above an upper predetermined limit and below a lower predetermined limit, and low attenuation for signals having optical frequencies lying between said upper and lower limits, which comprises: a substrate having a first, uniform index of refraction; and a layer of light-conducting material overlaid on said substrate, said layer having a second index of refraction which varies periodically along the direction of propagation of said filter.
Claim 29
Dependent Claim
25 words
The optical band-pass filter according to claim 20 wherein said periodic variation is a sinusoidal variation in the optical dielectric constant according to the equation:
Claim 30
Dependent Claim
14 words
the optical band-pass filter according to claim 20 wherein said periodic variation is non-sinusoidal.
Claim 31
Dependent Claim
24 words
The optical band-pass filter according to claim 20 further comprising means for varying the periodicity of said periodic variation in said index of refraction.
Claim 32
Dependent Claim
88 words
An optical band-pass filter having a high attenuation for optical signals having frequencies above an upper predetermined limit and below a lower predeterMined limit, and low attenuation for signals having optical frequencies lying between said upper and lower limits, which comprises: a substrate having a first index of refraction which varies periodically along the direction of propagation in at least the vicinity of the optical layer of said filter; and a layer of light-conducting material overlaid on said substrate, said layer having a second, uniform index of refraction.
Claim 33
Dependent Claim
88 words
An optical band-pass filter having a high attenuation for optical signals having frequencies above an upper predetermined limit and below a lower predeterMined limit, and low attenuation for signals having optical frequencies lying between said upper and lower limits, which comprises: a substrate having a first index of refraction which varies periodically along the direction of propagation in at least the vicinity of the optical layer of said filter; and a layer of light-conducting material overlaid on said substrate, said layer having a second, uniform index of refraction.
Claim 34
Dependent Claim
25 words
The optical band-pass filter according to claim 24 wherein said periodic variation is a sinusoidal variation in the optical dielectric constant according to the equation:
Claim 35
Dependent Claim
14 words
The optical band-pass filter according to claim 24 wherein said periodic variation is non-sinusoidal.
Claim 36
Dependent Claim
24 words
The optical band-pass filter according to claim 24 further comprising means for varying the periodicity of said periodic variation in said index of refraction.
Claim 37
Dependent Claim
54 words
An optical waveguide filter which comprises: a cylindrical core of light-conducting material having a first, uniform index of refraction in the direction of propagation; and at least one cylindrical layer of cladding about said core, said layer having a second index of refraction which varies periodically along the direction of propagation of said waveguide.
Claim 38
Dependent Claim
54 words
An optical waveguide filter which comprises: a cylindrical core of light-conducting material having a first, uniform index of refraction in the direction of propagation; and at least one cylindrical layer of cladding about said core, said layer having a second index of refraction which varies periodically along the direction of propagation of said waveguide.
Claim 39
Dependent Claim
18 words
The filter according to claim 28 wherein said core has, in addition, a radial index of refraction gradient.
Claim 40
Dependent Claim
23 words
The filter according to claim 28 wherein said at least one layer of cladding has, in addition, a radial index of refraction gradient.
Claim 41
Dependent Claim
23 words
The filter according to claim 28 wherein said periodic variation is a sinusoidal variation in the optical dielectric constant, according to the equation:
Claim 42
Dependent Claim
12 words
The device according to claim 28 wherein said periodic variation is non-sinusoidal.
Claim 43
Dependent Claim
21 words
The device according to claim 28 further comprising means for altering the periodicity of the variation in the index of refraction.
Claim 44
Dependent Claim
59 words
An optical transmission system, which comprises: an optical waveguide comprising a cylindrical core and at least one cylindrical layer of cladding about said core, said cladding having a periodic variation in the index of refraction thereof; means for introducing modulated optical information into one end of said waveguide; and an optical demodulator proximate the other end of said waveguide.
Claim 45
Dependent Claim
59 words
An optical transmission system, which comprises: an optical waveguide comprising a cylindrical core and at least one cylindrical layer of cladding about said core, said cladding having a periodic variation in the index of refraction thereof; means for introducing modulated optical information into one end of said waveguide; and an optical demodulator proximate the other end of said waveguide.
Claim 46
Dependent Claim
30 words
The optical transmission system according to claim 34 further comprising: at least one amplifying means, positioned intermediate the ends of said waveguide, for amplifying the optical information in said waveguide.
Claim 47
Dependent Claim
31 words
The optical transmission system according to claim 34 wherein said introducing means comprises: an optical maser; and an optical modulator positioned intermediate the optical maser and the end of said waveguide.
Claim 48
Dependent Claim
57 words
An optical waveguide filter which comprises: a cylindrical core of light-conducting material having a first index of refraction which varies periodically along the direction of propagation of the waveguide; and at least one cylindrical layer of cladding about said core, said layer having a second, uniform index of refraction in the direction of propagation of the waveguide.
Claim 49
Dependent Claim
57 words
An optical waveguide filter which comprises: a cylindrical core of light-conducting material having a first index of refraction which varies periodically along the direction of propagation of the waveguide; and at least one cylindrical layer of cladding about said core, said layer having a second, uniform index of refraction in the direction of propagation of the waveguide.
Claim 50
Dependent Claim
24 words
The waveguide filter according to claim 37 wherein said periodic variation is a sinusoidal variation in the optical dielectric constant according to the equation:
Claim 51
Dependent Claim
12 words
The device according to claim 37 wherein said periodic variation is non-sinusoidal.
Claim 52
Dependent Claim
21 words
The device according to claim 37 further comprising means for altering the periodicity of the variation in the index of refraction.
Claim 53
Dependent Claim
72 words
An optical transmission system, which comprises: an optical waveguide comprising a cylindrical core having a periodic variation in the index of refraction in the direction of propagation of the waveguide, and at least one cylindrical layer of cladding about said core, said cladding having a uniform index of refraction; means for introducing modulated optical information into one end of said waveguide; and an optical demodulator proximate the other end of said waveguide.
Claim 54
Dependent Claim
72 words
An optical transmission system, which comprises: an optical waveguide comprising a cylindrical core having a periodic variation in the index of refraction in the direction of propagation of the waveguide, and at least one cylindrical layer of cladding about said core, said cladding having a uniform index of refraction; means for introducing modulated optical information into one end of said waveguide; and an optical demodulator proximate the other end of said waveguide.
Claim 55
Dependent Claim
30 words
The optical transmission system according to claim 41 further comprising: at least one amplifying means, positioned intermediate the ends of said waveguide, for amplifying the optical information in said waveguide.
Claim 56
Dependent Claim
31 words
The optical transmission system according to claim 41 wherein said introducing means comprises: an optical maser; and an optical modulator positioned intermediate the optical maser and the end of said waveguide.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-10-27 | 1979-04-28 | 1979-10-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-10-27 | 1983-04-28 | 1983-10-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-10-27 | 1987-04-28 | 1987-10-28 | $7700.00 | Window Closed / Lapsed |