US3924931A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Integrated optical signal processing system
Assignee: RTX Corp
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Filing: 1974-04-01
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Granted: 1975-12-09
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Expires: 1994-04-01
Abstract
Abstract An electrooptic thin film wave guide structure is used to deflect an incident optical beam such as a laser beam. This structure is made of an electrooptic thin film material of high resistivity which can be obtained by either epitaxial growth on a conducting substrate or by mechanical thinning of a bulk wafer. A single electrode or multiple electrodes are fabricated on the thin film material. By applying a voltage to the electrode or electrodes, a refractive index change is produced in the thin film material and the incident laser beam is deflected within the plane of the thin film material. By forming a plurality of electrodes on the thin film material and applying properly programmed voltage wave forms to the electrodes, the refractive index profile in the plane of the thin film material may be varied to produce a high speed optical switching function. This optical switch can be used as a multiplexing terminal to steer a single or multiple beams in either time, space or frequency domains.
Inventors
- 👤 Peter K Cheo
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 18:16
CPC Classifications
G; G02; G02F; G02F1/00; G02F1/29; G02F1/33; G02F1/335; G02F1/295; G02F1/2955
Claims Analysis
Total Claims: 22
Claim 1
Independent Claim
240 words
A thin film electrooptic switch comprising an electrically conducting substrate, a high resistivity thin film material fabricated on the surface of said substrate, a plurality of flat, metallic electrodes located parallel to each other on the surface of said thin film material and spaced from each other across the width of said thin film material, means for applying a selected voltage to selected ones of said electrodes to produce a potential difference between each of said selected electrodes and said substrate and thereby generate an intense electric field between each of said selected electrodes and said substrate, said electric field being oriented perpendicular to the plane of said thin film material and producing in said thin film material a spatial variation in the index of refraction thereof across the width of said thin film material, means for coupling a coherent optical beam into said thin film material and causing said optical beam to propagate as a guided optical wave along an optical waveguide consisting of said thin film material and said substrate, said wave front propagating substantially parallel to the direction of said electrodes and intersecting the portion of the thin film material containing the spatial variation in the index of refraction whereby a phase variation is produced in said optical beam and said beam is selectively deflected in the plane of said thin film material, and means for coupling said deflected optical beam out of said thin film material.
Claim 2
Dependent Claim
240 words
A thin film electrooptic switch comprising an electrically conducting substrate, a high resistivity thin film material fabricated on the surface of said substrate, a plurality of flat, metallic electrodes located parallel to each other on the surface of said thin film material and spaced from each other across the width of said thin film material, means for applying a selected voltage to selected ones of said electrodes to produce a potential difference between each of said selected electrodes and said substrate and thereby generate an intense electric field between each of said selected electrodes and said substrate, said electric field being oriented perpendicular to the plane of said thin film material and producing in said thin film material a spatial variation in the index of refraction thereof across the width of said thin film material, means for coupling a coherent optical beam into said thin film material and causing said optical beam to propagate as a guided optical wave along an optical waveguide consisting of said thin film material and said substrate, said wave front propagating substantially parallel to the direction of said electrodes and intersecting the portion of the thin film material containing the spatial variation in the index of refraction whereby a phase variation is produced in said optical beam and said beam is selectively deflected in the plane of said thin film material, and means for coupling said deflected optical beam out of said thin film material.
Claim 3
Dependent Claim
67 words
Apparatus as in claim 1 in which said means for applying a voltage to selected ones of said electrodes includes means for applying a voltage to each said electrode in staircase fashion whereby the minimum voltage is applied to the electrode at one side of said thin film material and the maximum voltage is applied to the electrode at the opposite side of said thin film material.
Claim 4
Dependent Claim
33 words
Apparatus as in claim 2 in which the maximum voltage applied to said electrodes by said voltage applying means is that required to produce a pi phase shift in said guided optical wave.
Claim 5
Dependent Claim
34 words
Apparatus as in claim 1 in which said means for applying a voltage to selected ones of said electrodes includes means for applying a voltage of different polarities and amplitudes to said selected electrodes.
Claim 6
Dependent Claim
52 words
Apparatus as in claim 1 and further including means including said voltage applying means for varying the index of refraction across the width of said thin film material in a manner whereby a portion of said beam is deflected to a plurality of locations in the plane of said thin film material.
Claim 7
Dependent Claim
31 words
Apparatus as in claim 5 in which said coupling means includes means for coupling the portion of said beam deflected to said plurality of locations out of said thin film material.
Claim 8
Dependent Claim
16 words
Apparatus as in claim 1 in which each of said electrodes is rectangular in surface area.
Claim 9
Dependent Claim
16 words
Apparatus as in claim 1 in which each of said electrodes is triangular in surface area.
Claim 10
Dependent Claim
15 words
Apparatus as in claim 1 in which said thin film material comprises a single crystal.
Claim 11
Dependent Claim
27 words
Apparatus as in claim 1 in which said means for coupling said coherent optical beam into and out of said thin film material includes optical fiber means.
Claim 12
Dependent Claim
42 words
Apparatus as in claim 1 in which said means for coupling said coherent optical beam into and out of said thin film material includes first and second optical gratings etched into said thin film on opposite sides of said plurality of electrodes.
Claim 13
Dependent Claim
15 words
Apparatus as in claim 1 in which said coherent optical beam comprises a laser beam.
Claim 14
Dependent Claim
19 words
Apparatus as in claim 1 in which said optical beam comprises the output beam from a light emitting diode.
Claim 15
Dependent Claim
24 words
Apparatus as in claim 1 and including detector means located in the path of said optical beam coupled out of said thin film material.
Claim 16
Dependent Claim
37 words
Apparatus as in claim 1 and including first lens means fabricated in said thin film material and located between said means for coupling said coherent optical beam into said thin film material and said plurality of electrodes.
Claim 17
Dependent Claim
38 words
Apparatus as in claim 1 and including second lens means fabricated in said thin film material and located between said plurality of electrodes and said means for coupling said coherent optical beam out of said thin film material.
Claim 18
Dependent Claim
42 words
Apparatus as in claim 1 and including means for coupling a plurality of coherent optical beams into said thin film material, each of said optical beams being selectively deflected in the plane of said thin film by said index of refraction variation.
Claim 19
Dependent Claim
45 words
Apparatus as in claim 1 and including means for applying an alternating voltage wave form to said selected electrodes in a preselected pattern whereby a portion of said optical beam is simultaneously deflected along a plurality of paths within the plane of said thin film.
Claim 20
Dependent Claim
29 words
Apparatus as in claim 18 and including means for simultaneously coupling the portions of said deflected optical beam from said plurality of paths out of said thin film material.
Claim 21
Dependent Claim
98 words
A three dimensional switch comprising a substrate of electrically conductive material, first and second electrooptically active thin films fabricated on said substrate on opposite sides thereof, means for coupling an electromagnetic wave into said first thin film, electrode means for electrooptically producing a spatial variation in the index of refraction of said first thin film to produce a deflection of said wave in the plane of said thin film material, means for coupling said wave from said first thin film into said second thin film, and means for coupling said deflected wave out of said second thin film.
Claim 22
Dependent Claim
98 words
A three dimensional switch comprising a substrate of electrically conductive material, first and second electrooptically active thin films fabricated on said substrate on opposite sides thereof, means for coupling an electromagnetic wave into said first thin film, electrode means for electrooptically producing a spatial variation in the index of refraction of said first thin film to produce a deflection of said wave in the plane of said thin film material, means for coupling said wave from said first thin film into said second thin film, and means for coupling said deflected wave out of said second thin film.
References Cited (Backward Citations)
US3695745A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-12-08 | 1979-06-09 | 1979-12-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-12-08 | 1983-06-09 | 1983-12-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-12-08 | 1987-06-09 | 1987-12-09 | $7700.00 | Window Closed / Lapsed |