Acoustooptic transducer arrangement for optical fibers

• US 4,907,856 A
• Filed: 08/29/1988
• Issued: 03/13/1990
• Est. Priority Date: 08/29/1988
• Status: Expired due to Term

• Current Assignee: Motorola, Inc. (Motorola Solutions, Inc.)
• Original Assignee: Motorola, Inc. (Motorola Solutions, Inc.)
• Inventors: Hickernell, Fred S.
• Primary Examiner(s): Sikes, William L.
• Assistant Examiner(s): Wise, Robert E.
• Application Number:
  US07/237,936
• Time in Patent Office: 561 Days
• Field of Search: 350/96.29, 350/96.30
• US Class Current: 385/1
• CPC Class Codes: G02F 1/0134 in optical waveguides

Abstract

An acoustooptic transducer includes a base and cap which may be mated axially along a certain length of an optical fiber. The base and cap each include a semicircular channel fabricated along one axis. A zinc oxide layer is sandwiched between two metal layers in each of the semicircular channels. When the cap and base are mated, each of the semicircular channels of metal and zinc oxide correspond to form coaxial cylindrical channels of zinc oxide sandwiched by layers of metal surrounding the fiber. Under an applied electrical force, to electrodes of the metal layers, the zinc oxide produces focused acoustic waves for coupling to the light transmitted through the optical fiber. In another embodiment of this invention, the layer of zinc oxide sandwiched between the metal layers may be applied directly to a predetermined length of the optical fiber.

Claims

1. An acoustooptic transducer for acoustooptic coupling to light waves traveling through an optical fiber, said acoustooptic transducer arrangement comprising:

body means including first and second portions, each of said first and second portion of said body means including channel means located axially along a surface of each portion and said channel means adapted to circumscribe said optical fiber;

piezoelectric means disposed about the surface of said channel means of said first and second portions of said body means, said piezoelectric means operating in response to an electric signal to produce an acoustic wave focused upon said optical fiber;

said optical fiber being positioned directly in contact with said piezoelectric means so that a channel means circumscribes a predetermined length of optical fiber; and

said first and second portions of said body means being positioned about said optical fiber so that said optical fiber is in direct contact with said piezoelectric means of said channel means, said first and second portions being bonded so that said piezoelectric means is coaxially oriented along said predetermined length of said optical fiber, whereby said acoustic waves are focused on said transmitted light waves of said optical fiber.

2. An acoustooptic transducer as claimed in claim 1, said channel means of said first and second portions of said body means each including semicircular cavities along said surface of said first and second portions of said body means.

3. An acoustooptic transducer as claimed in claim 2, wherein said first and second portions of said body means are substantially rectangular in shape.

4. An acoustooptic transducer as claimed in claim 2, wherein said first and second portions of said body means are substantially cylindrical in shape.

5. An acoustooptic transducer as claimed in claim 2, wherein said first and second portions of said body means are fabricated substantially of silicon.

6. An acoustooptic transducer as claimed in claim 2, wherein first and second portions of said body means are fabricated substantially of fused quartz.

7. An acoustooptic transducer as claimed in claim 2, wherein said first and second portions of said body means are fabricated substantially of plastic.

8. An acoustooptic transducer as claimed in claim 2, said piezoelectric means including:

first conductive layer means disposed along a surface of said semicircular cavities;

piezoelectric layer means being deposited over said first conductive layer means along said surface of said semicircular cavities; and

second conductive layers means deposited over said piezoelectric layer means along said surface of said semicircular cavities.

9. An acoustooptic transducer as claimed in claim 8, wherein said first and second conductive layer means each includes a corresponding first and second electrode means, said first electrode means being connected to said first conductive layer means and said second electrode means being connected to said second conductive layer means, said first and second electrode means being electrically isolated from one another.

10. An acoustooptic transducer as claimed in claim 8, wherein said first and second conductive layer means are comprised of metal means.

11. An acoustooptic transducer as claimed in claim 10, wherein said metal means comprises aluminum.

12. An acoustooptic transducer as claimed in claim 10, wherein said metal means comprises copper.

13. An acoustooptic transducer as claimed in claim 8, wherein said piezoelectric layer means comprises zinc oxide (ZnO).

14. An acoustooptic transducer as claimed in claim 8, wherein there is further included an electric source connected to said first and second electrode means, said electric source supplying a voltage to said piezoelectric layer means for the production of said acoustic waves.

15. An acoustooptic transducer as claimed in claim 8, wherein said first and second electrode means includes digit means being interdigitally aligned, so that said digit means of said first electrode means are alternately interleaved with said digit means of said second electrode means.

16. A method for fabricating an acoustooptic transducer, said acoustooptic transducer including first and second portions of a body for placing said transducer in contact with an optical fiber, said first and second portions of said body each including a corresponding semicircular channel for circumscribing said optical fiber, said method for fabrication of an acoustooptic transducer comprising the steps of:

depositing a first conductive layer about said semicircular channels of said first and second portions of said body;

second depositing a piezoelectric layer over said first conductive layer along said semicircular channel of said first and second portions of said body; and

third depositing a second conductive layer over said piezoelectric layer along said semicircular channel of said first and second portions of said body.

17. A method for fabrication of an acoustooptic transducer as claimed in claim 16, wherein there is further included the steps of:

first attaching a first electrode to said first conductive layer;

second attaching a second electrode to said second conductive layer; and

isolating said first and said second electrically from one another.

18. A method for fabrication of an acoustooptic transducer as claimed in claim 17 wherein there is further included the step of attaching said first and second portions of said body about an optical fiber so that said semicircular channels with said deposited layers circumscribe said optical fiber.

19. A method for fabrication of an acoustooptic transducer as claimed in claim 18, wherein there is further included the step of exciting said piezoelectric layer by application of an electrical source to said first and second conductive layers via said first and second electrodes.