Hybrid electro-optic cable for free space laser antennas
A hybrid cable comprising an optical fiber, an intermediate layer surrounding the optical fiber, and an electrically insulating jacket surrounding the intermediate layer. The intermediate layers include a collection of metallic strands. The hybrid cable may be used to establish simultaneous electrical and fiber-optic connection between two communication devices. Thus, the two communication devices may simultaneously transfer optical signals through the optical fiber and perform any of various electrical functions (power transfer, eye safety control) through the metallic strands. For example, an optical transceiver may couple to an optical antenna unit through the hybrid cable. Such an optical transceiver may serve as part of a point-to-point link, a point-to-multipoint link, and/or, a link between a primary transceiver unit and an optical router.
1. A communication cable comprising:
a first optical fiber;
a first intermediate layer surrounding the first optical fiber, wherein the first intermediate layer includes a first electrical conductor, wherein the first electrical conductor comprises a first collection of metallic strands;
a first electrically insulating jacket surrounding the first intermediate layer;
a first metallic ferrule which couples to the first electrical conductor at a first end of the communication cable; and
a first crimping sleeve configured to slide up over a rear portion of the first metallic ferrule and to crimp the first collection of metallic strands onto said rear portion.
2. The communication cable of claim 1 , wherein the first intermediate layer also includes first non-conductive strengthening material.
3. The communication cable of claim 1 , wherein the first collection of metallic fibers are braided.
4. The communication cable of claim 1 , wherein the first collection of metallic fibers surround the first optical fiber.
5. The communication cable of claim 1 further comprising:
a second optical fiber;
a second intermediate layer surrounding the second optical fiber; and
wherein the first electrically insulating jacket also surrounds the second intermediate layer;
wherein the second intermediate layer includes a second electrical conductor.
6. The communication cable of claim 5 , wherein the first electrically insulating jacket has a zipcord format.
7. The communication cable of claim 1 , further comprising a first electrically insulating coupling nut surrounding the first metallic ferrule.
8. A method for terminating an opto-electronic cable with an opto-electronic connector, wherein the opto-electronic cable has an optical fiber, an intermediate layer comprising metallic strands surrounding the optical fiber and an electrically insulating jacket surrounding the metallic strands, the method comprising:
fixing the optical fiber in a fiber cavity within a metallic ferrule;
placing the metallic strands in proximity to a first external end portion of the metallic ferrule; and
sliding a metallic crimping sleeve over the metallic strands to crimp the metallic strands onto the first external end portion of the metallic ferrule thereby establishing an electrical contact.
9. The method of claim 8 further comprising sliding a strain relief boot over the metallic crimping sleeve.
10. The method of claim 8 further comprising twisting the metallic strands into a bundle prior to placing the metallic strands in proximity to a first external end portion of the metallic ferrule.
11. A communication system comprising:
a hybrid cable comprising a first optical fiber, a first intermediate layer surrounding the first optical fiber, a first jacket surrounding the first intermediate layer, wherein the first intermediate layer includes a first electrical conductor, wherein the first intermediate layer also includes first non-conductive strengthening material;
a first communication device coupled to the first optical fiber and the first electrical conductor at a first end of the hybrid cable;
a second communication device coupled to first optical fiber and the first electrical conductor at a second end of the hybrid cable.
12. The communication system of claim 11 , wherein the first electrical conductor comprises a collection of metallic strands.
13. The communication system of claim 12 , wherein the collection of metallic strands are distributed within the first intermediate layer so as to surround the first optical fiber.
14. The communication system of claim 11 , wherein the first communication device includes a power source configured to deliver electrical power to the second communication device through the first electrical conductor.
15. The communication system of claim 11 , where the first communication device includes a light source which is configured to generate a light beam which is to be modulated and transmitted through the first optical fiber to the second communication device.
16. The communication system of claim 11 , wherein the first communication device includes an optical receiver for demodulating data from an optical signal received through the first optical fiber.
17. The communication system of claim 11 , wherein the second communication device is an optical antenna unit configured to receive a modulated light beam from the first optical fiber and to transmit the first light beam into the atmosphere.
18. The communication system of claim 11 , wherein the second communication device is an optical antenna unit configured to receive a portion of a modulated light beam from the atmosphere and to send said portion to the first communication device through the first optical fiber.
19. The communication system of claim 11 , wherein the second communication device is an optical antenna unit, wherein the optical antenna unit includes a resistive heating element which receives electrical power transmitted through the first electrical conductor from the first communication device.
20. The communication system of claim 11 , wherein the first communication device includes a light source and a safety control system, wherein the safety control system is configured to detect an open loop condition in an electrical circuit which includes the first electrical conductor, wherein the safety control system is configured to decrease the emitted power of a light source in response to detecting the open loop condition.
21. The communication system of claim 11 , wherein the first communication device and second communication device are fiber optic transceivers.
22. The communication system of claim 11 , wherein the first communication device is situated at a first location internal to a building, wherein the second communication device is an optical antenna unit situated at a second location external to said building.
23. The communication system of claim 22 , wherein the first communication device is configured for coupling to a host computer.
24. The communication system of claim 11 , wherein the first communication device is a point-to-point transceiver unit and the second communication device is an optical antenna unit.
25. The communication system of claim 11 , wherein the first communication device is a point-to-multipoint optical transceiver unit and the second communication device is an optical antenna unit.
26. The communication system of claim 11 , wherein the first communication device is configured for bi-directional transfer of optical signals through the first optical fiber.
27. The communication system of claim 11 , wherein hybrid cable includes ST-type terminations.
28. A communication system comprising:
a hybrid cable comprising a first optical fiber, a first intermediate layer surrounding the first optical fiber, a first jacket surrounding the first intermediate layer, wherein the first intermediate layer includes a first electrical conductor;
a first communication device coupled to the first optical fiber and the first electrical conductor at a first end of the hybrid cable; and
a second communication device coupled to first optical fiber and the first electrical conductor at a second end of the hybrid cable;
wherein the first communication device includes a light source and a safety control system, wherein the safety control system is configured to detect change in an electrical quantity associated with an electrical circuit which includes the first electrical conductor, wherein the safety control system is configured to decrease the power emitted by a light source in response to detecting the change.