US4401363A
Expired / Lapsed
US
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Optical waveguide and method of propagating waves therein
Assignee: National Research Development Corp UK
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Filing: 1980-09-29
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Granted: 1983-08-30
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Expires: 2000-09-29
Abstract
Abstract Conventional optical waveguides are of very small diameter making handling and coupling difficult. Also the HE 11 mode is used and this can give rise to contamination where inhomogeneities arise in the waveguide. The waveguide of the present invention has a tube of higher permittivity optical material, with a core of lower permittivity optical material and cladding again of lower permittivity material. The critical dimension is the thickness of the tube and the tube diameter can therefore be made very much larger than that of the conventional optical waveguide. Such a waveguide when properly excited will support the HE 11 wave as a single mode or alternatively the TE 01 mode as a pure wave. Methods of launching and propagating these modes are described.
Inventors
- 👤 Harold E. M. Barlow
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 18:29
CPC Classifications
H; H04; H04B; H04B10/00; H04B10/25; H04B10/2581; G; G02; G02B; G02B6/00; G02B6/02
Claims Analysis
Total Claims: 17
Claim 1
Independent Claim
202 words
A transmission system comprising means for generating periodically varying signals, an optical waveguide having a tubular wall capable of supporting propagation in all of the modes HE 11 , TE 01 and TM 01 , and means for handling waves in up to but not more than two of the said modes but not both the TE 01 and TM 01 modes, on the waveguide, the optical waveguide comprising a tube of a first solid optical material having a wall thickness equal to, or greater than, substantially half the maximum radial wavelength of the said waves in the first optical material and such that the phase-change of the waves within the tube wall and normal to the wall surfaces is sufficiently small to ensure that the electromagnetic fields inside and outside the tube walls, due to the said waves, are evanescent, and the tube containing and being surrounded by a second solid optical material or materials, the first optical material being of higher permittivity than the second optical material or each of the second optical materials, and the first optical material and the second optical material or materials each having a specific dielectric conductivity of less than 10 -4 mhos per meter.
Claim 2
Dependent Claim
202 words
A transmission system comprising means for generating periodically varying signals, an optical waveguide having a tubular wall capable of supporting propagation in all of the modes HE 11 , TE 01 and TM 01 , and means for handling waves in up to but not more than two of the said modes but not both the TE 01 and TM 01 modes, on the waveguide, the optical waveguide comprising a tube of a first solid optical material having a wall thickness equal to, or greater than, substantially half the maximum radial wavelength of the said waves in the first optical material and such that the phase-change of the waves within the tube wall and normal to the wall surfaces is sufficiently small to ensure that the electromagnetic fields inside and outside the tube walls, due to the said waves, are evanescent, and the tube containing and being surrounded by a second solid optical material or materials, the first optical material being of higher permittivity than the second optical material or each of the second optical materials, and the first optical material and the second optical material or materials each having a specific dielectric conductivity of less than 10 -4 mhos per meter.
Claim 3
Dependent Claim
28 words
A transmission system according to claim 1 wherein the attenuation constant radial to, but inside and outside, the tube wall is at least 10 6 nepers per meter.
Claim 4
Dependent Claim
128 words
A transmission system according to claim 1 wherein the tube is circular in cross-section, the tube is filled with and surrounded by second optical materials having relative permittivities of ε r .sbsb.1 and ε r .sbsb.3, respectively, and the attenuation constants a 1 and a 3 radial to the tube in the material filling the tube and the material surrounding the tube, respectively, are each at least 10 6 as calculated from a.sub.1.sup.2 =ω.sup.2 μ.sub.o ε.sub.o (ε.sub.r.sbsb.2 -ε.sub.r.sbsb.1)-b.sub.2.sup.2, and a.sub.3.sup.2 =ω.sup.2 μ.sub.o ε.sub.o (ε.sub.r.sbsb.2 -ε.sub.r.sbsb.3)-b.sub.2.sup.2 where ω=the angular frequency of the predetermined signals, μ o =the permeability of free space, ε o =the permittivity of free space, ε r .sbsb.2 =the permittivity of the first optical material, b 2 =(π/δ), and ε=the thickness of the tube in meters.
Claim 5
Dependent Claim
36 words
A transmission system according to claim 1 wherein the thickness of the tube wall is small relative to the minimum distance between the longitudinal axis of the tube and the inner surface of the tube wall.
Claim 6
Dependent Claim
48 words
A transmission system according to claim 4 wherein the tube is circular in cross-section and the ratio of the radius of the outer surface of the tube divided by the radius of the inner surface thereof is in the range: greater than 1 to not greater than 3.
Claim 7
Dependent Claim
26 words
A transmission system according to claim 1 wherein the first and second optical materials merge together gradually at the outside and/or the inside of the tube.
Claim 8
Dependent Claim
36 words
A transmission system according to claim 1 wherein the tube is surrounded by at least one further tube of relatively high permittivity optical material, the tubes being separated by optical material of relatively low permittivity material.
Claim 9
Dependent Claim
66 words
A transmission system according to claim 1 wherein one of the modes TE 01 and TM 01 is handled by said handling means which comprises launching means having a coherent light source adapted to direct first and second light beams in phase opposition towards first and second areas, respectively, of one end of the tube, the first and second areas being positioned diametrically opposite one another.
Claim 10
Dependent Claim
54 words
A transmission system according to claim 8 including beam splitter means for generating the first and second light beams from light from the said source, first and second optical fibres for directing the first and second light beams to the first and second areas, respectively, and means for straining the first or second fibres.
Claim 11
Dependent Claim
92 words
A transmission system according to claim 1 wherein one of the modes TE 01 and TM 01 is handled by said handling means which comprises receiving means having a light-sensitive device for receiving light from first and second areas of one end of the tube by way of first and second light paths, respectively, the first and second areas being positioned diametrically opposite one another and the first and second light paths being such that light in phase opposition in the first and second areas is in phase at the light-sensitive device.
Claim 12
Dependent Claim
31 words
A transmission system according to claim 10 wherein the first and second light paths comprise first and second optical fibres, respectively, and means for straining one of the fibres is provided.
Claim 13
Dependent Claim
64 words
A transmission system according to claim 1, wherein one of the modes TE 01 and TM 01 is handled by said handling means which comprises launching means having a coherent light source for directing first and second light beams in phase towards first and second areas, respectively, of one end of the tube, the first and second areas being positioned diametrically opposite one another.
Claim 14
Dependent Claim
91 words
A transmission system according to claim 1, wherein one of the modes TE 01 and TM 01 is handled by said handling means which comprises receiving means having a light-sensitive device for receiving light from first and second areas of one end of the tube by way of first and second light paths, respectively, the first and second areas being positioned diametrically opposite one another and the first and second light paths being such that light in phase in the first and second areas is in phase at the light-sensitive device.
Claim 15
Independent Claim
212 words
A method of transmitting signals comprising generating periodically varying signals, and launching electromagnetic waves corresponding to the said signals in up to but not more than two of the modes HE 11 , TE 01 and TM 01 but not both the TE 01 and TM 01 modes on a waveguide and deriving signals from waves propagating in the waveguide, the waveguide comprising a hollow tube capable of supporting all of the said modes, the tube being constituted by a first solid optical material having a wall thickness equal to or greater than, substantially half the maximum radial wavelength of the said waves in the first optical material, the tube being such that the variation of phase of the waves within the tube wall and normal to the wall surfaces is sufficiently small to ensure that the electromagnetic fields inside and outside the tube wall, due to the said waves, are evanescent, the tube containing and being surrounded by a second solid optical material or materials, the first optical material being of higher permittivity than the second optical material or each of the second optical materials, and the first optical material and the second optical material or materials each having a specific dielectric conductivity of less than 10 -4 mhos per meter.
Claim 16
Independent Claim
212 words
A method of transmitting signals comprising generating periodically varying signals, and launching electromagnetic waves corresponding to the said signals in up to but not more than two of the modes HE 11 , TE 01 and TM 01 but not both the TE 01 and TM 01 modes on a waveguide and deriving signals from waves propagating in the waveguide, the waveguide comprising a hollow tube capable of supporting all of the said modes, the tube being constituted by a first solid optical material having a wall thickness equal to or greater than, substantially half the maximum radial wavelength of the said waves in the first optical material, the tube being such that the variation of phase of the waves within the tube wall and normal to the wall surfaces is sufficiently small to ensure that the electromagnetic fields inside and outside the tube wall, due to the said waves, are evanescent, the tube containing and being surrounded by a second solid optical material or materials, the first optical material being of higher permittivity than the second optical material or each of the second optical materials, and the first optical material and the second optical material or materials each having a specific dielectric conductivity of less than 10 -4 mhos per meter.
Claim 17
Dependent Claim
54 words
A method according to claim 14, including launching the waves in one of the TE 01 and TM 01 modes by transmitting first and second oppositely phased light signals to first and second areas, respectively, of an end of the tube, the areas being on opposite sides of the longitudinal axis of the tube.
References Cited (Backward Citations)
GB764737A
Cited
US3386043A
Cited
GB1339599A
Cited
GB1362757A
Cited
GB1434977A
Cited
US3973828A
Cited
US3877912A
Cited
GB1543242A
Cited
GB1569132A
Cited
GB1496324A
Cited
GB1475478A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1986-08-29 | 1987-02-28 | 1987-08-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1990-08-29 | 1991-02-28 | 1991-08-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1994-08-29 | 1995-02-28 | 1995-08-30 | $7700.00 | Window Closed / Lapsed |