US3864019A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Optical film-fiber coupler
Assignee: AT&T Inc
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Filing: 1973-11-15
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Granted: 1975-02-04
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Expires: 1993-11-15
Abstract
Abstract There is disclosed an arrangement for coupling guided optical waves from thin-film waveguides to fiber waveguides, and vice versa. The thin film in the former type of guide is provided with an end region which is gradually tapered in thickness along the path of the wave to be guided therein to a cut-off value for the wave. This tapered region of the film causes the wave to propagate out of the film into the lower refractive index substrate of the guide along a small angle with respect to the film-substrate interface. Situated in the substrate slightly below the film-substrate interface is a cavity having a crosssectional shape and cross-sectional dimensions adapted for receiving an end of the fiber waveguide. By properly selecting the orientation and position of the cavity in the substrate, and of the fiber in the cavity, the fiber can be made to intercept the wave coupled out of the film. To insure efficient coupling of the wave into the fiber, the cavity is provided with a hemispherical end shape and is filled with a transparent material having a refractive index exceeding that of the substrate. A hemispherical lens is thereby formed which focuses and directs the wave into the fiber. Efficient coupling of the guided wave from the thin film to the fiber, or from the fiber to the thin film, is thus possible.
Inventors
- 👤 Gerald Smolinsky
- 👤 Ping King Tien
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 09:43
CPC Classifications
G; G02; G02B; G02B6/00; G02B6/24; G02B6/26; G02B6/30; G02B6/305; G02B6/262; G02B6/36; G02B6/38; G02B6/3801
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
226 words
An arrangement for coupling a wave of optical electromagnetic radiation between a thin-film optical waveguide and a fiber optical waveguide, said thin-film waveguide comprising a transparent substrate, a transparent dielectric film formed on a major surface of said substrate, said film having an index of refraction exceeding that of said substrate and a thickness proportioned for guiding said wave of optical electromagnetic radiation, said fiber waveguide comprising an elongated transparent fiber having cross-sectional dimensions and a refractive index distribution also proportioned for guiding said wave, said arrangement being characterized in that said film has an end region that is gradually tapered in thickness along the intended path of said wave to be guided therein to a cut-off point at which said film is incapable of supportiNg said wave as guided mode, said tapered end region providing emergence of said wave from said film along a path in said substrate, and in that said substrate includes a region defining a cavity disposed to intercept the intended path of said wave in said substrate and into which a portion of the length of said fiber is inserted said cavity having an essentially hemispherical end shape and being filled with a transparent filler material having an index of refraction exceeding that of said substrate to form an essentially hemispherical lens in said substrate at the end of said cavity.
Claim 2
Dependent Claim
226 words
An arrangement for coupling a wave of optical electromagnetic radiation between a thin-film optical waveguide and a fiber optical waveguide, said thin-film waveguide comprising a transparent substrate, a transparent dielectric film formed on a major surface of said substrate, said film having an index of refraction exceeding that of said substrate and a thickness proportioned for guiding said wave of optical electromagnetic radiation, said fiber waveguide comprising an elongated transparent fiber having cross-sectional dimensions and a refractive index distribution also proportioned for guiding said wave, said arrangement being characterized in that said film has an end region that is gradually tapered in thickness along the intended path of said wave to be guided therein to a cut-off point at which said film is incapable of supportiNg said wave as guided mode, said tapered end region providing emergence of said wave from said film along a path in said substrate, and in that said substrate includes a region defining a cavity disposed to intercept the intended path of said wave in said substrate and into which a portion of the length of said fiber is inserted said cavity having an essentially hemispherical end shape and being filled with a transparent filler material having an index of refraction exceeding that of said substrate to form an essentially hemispherical lens in said substrate at the end of said cavity.
Claim 3
Dependent Claim
68 words
The coupling arrangement of claim 1 in which said film has an essentially uniform thickness of the order of the free space wavelength of said wave to be guided therein and in which the taper in the end region of said film is a substantially linear taper to zero thickeness extending over a distance of said film greater than 10 times the free space wavelength of said wave.
Claim 4
Dependent Claim
32 words
The coupling arrangement of claim 1 in which said transparent filler material is a liquid monomer capable of polymerization to provide firm attachment of said fiber to said substrate in said cavity.
Claim 5
Dependent Claim
32 words
The coupling arrangement of claim 1 in which said transparent filler material is a liquid cement which, when hardened, provides a firm attachment of said fiber to said substrate in said cavity.
Claim 6
Dependent Claim
31 words
The coupling arrangement of claim 1 in which said region of said substrate defines a cavity having a central axis which is essentially parallel to said major surface of said substrate.
Claim 7
Dependent Claim
34 words
The coupling arrangement of claim 1 in which said region of said substrate defines a cavity having a central axis which is essentially collinear with the intended path of said wave in said substrate.
Claim 8
Dependent Claim
214 words
The coupling arrangement of claim 1 in which said fiber is a first cylindrically shaped fiber waveguide having a substantially uniform index of refraction exceeding that of said substrate and a diameter in excess of about 100 times the free space wavelength of said wave to be guided therein, and including means external to said substrate for joining said first fiber waveguide to a second fiber waveguide having a guiding region with cross-sectional dimensions substantially less than the diameter of said first fiber waveguide, said joining means comprising a body having a first cavity at one end thereof of a cross-sectional diameter suitable for receiving said first fiber, a second cavity at the opposite end of said body of cross-sectional diameter substantially less than the diameter of said first cavity and suitable for receiving said second fiber, and a third cavity connecting said first cavity to said second cavity, said third cavity having a cross-sectional diameter which is gradually tapered from a value equal to that of said first cavity to a value no greater than that of said second cavity, said third cavity being filled with a transparent filler material having an index of refraction exceeding that of said body, whereby said wave propagating in said body is efficiently transferred between said fibers.
Claim 9
Dependent Claim
119 words
The coupling arrangement of claim 6 in which said fiber is a cylindrically shaped, cladded fiber waveguide having an inner core formed of a first transparent material and an outer cladding formed of a second transparent material of lower refractive index than that of said inner core, and in which said region of said substrate defines a cylindrically shaped cavity, the diameter of which gradually increases from a value essentially equal to the diameter of said inner core in a region along its central axis nearest to the cut-off point of said film to a value greater than the diameter of said outer cladding in a region along its central axis farthest from the cut-off point of said film.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-02-03 | 1978-08-05 | 1979-02-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-02-03 | 1982-08-05 | 1983-02-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-02-03 | 1986-08-05 | 1987-02-04 | $7700.00 | Window Closed / Lapsed |