APPARATUS FOR MODULAR IMPLEMENTATION OF MULTI-FUNCTION ACTIVE OPTICAL CABLES

• US 20140186023A1
• Filed: 12/19/2013
• Published: 07/03/2014
• Est. Priority Date: 12/29/2012
• Status: Active Grant

• Current Assignee: Zephyr Photonics
• Original Assignee: Zephyr Photonics
• Inventors: Louderback, Duane
• Granted Patent: US 9,160,452 B2
• Time in Patent Office: Days
• US Class Current: 398/16
• CPC Class Codes: G02B 6/3817 containing optical and electrical conductors cables including electrical and optical conductors H01B11/22; G02B6/3816 takes precedence
• CPC Class Codes: G02B 6/3885 Multicore or multichannel optical connectors, i.e. one single ferrule containing more than one fibre, e.g. ribbon type optical ribbon cable G02B6/4403, G02B6/448
• CPC Class Codes: G02B 6/4269 with heat sinks or radiation fins
• CPC Class Codes: G02B 6/4293 hybrid electrical and optical connections for transmitting electrical and optical signals
• CPC Class Codes: G02B 6/4416 Heterogeneous cables
• CPC Class Codes: G02B 6/4471 Terminating devices demountable connectors G02B6/3807; Cable clamps
• CPC Class Codes: H04B 10/038 using bypasses
• CPC Class Codes: H04B 10/071 using a reflected signal, e.g. using optical time domain reflectometers [OTDR]
• CPC Class Codes: H04B 10/077 using a supervisory or additional signal
• CPC Class Codes: H04B 10/0791 Fault location on the transmission path
• CPC Class Codes: H04B 10/0795 Performance monitoring; Measurement of transmission parameters
• CPC Class Codes: H04B 10/0797 Monitoring line amplifier or line repeater equipment
• CPC Class Codes: H04B 10/2581 Multimode transmission
• CPC Class Codes: H04B 10/807 Optical power feeding, i.e. transmitting power using an optical signal
• CPC Class Codes: Y10T 29/49117 Conductor or circuit manufacturing

Abstract

Apparatus enabling modular implementation of active optical cable (AOC) with multiple integrated functions including: integration of different types of data on the AOC via media conversion; distribution of electrical power over the AOC; electrical multiplexing data channels for optical fibers; integration of voltage regulators enabling AOC operation at different supply voltages; integration of voltage regulators to provide stable, low noise power source; ruggedized, blind-mateable electrical connectors; integration of electronics and optoelectronics inside a connector backshell; implementation of health monitoring and test channel enabling monitoring, test, and control of both ends of the AOC and monitoring and control of upstream systems and components; and enabling a form, fit, function replacement of existing electrical cables to improve SWaP, electromagnetic interference resiliency, length-bandwidth product, electromagnetic pulse resistance, signal integrity, system reliability, testability and maintenance. AOCs are customized for different connectors, pin-outs, electrical data combinations, power distribution and power supplies with minimal redesign/requalification.

Claims

1. An active optical cable apparatus comprising:

a cable having a first end and a second end and one or more optical fibers and zero or more electrical conductors;

an optoelectronic module at the first end and the second end of the cable comprising;

an electrical connector;

one or more boards having;

an optical engine comprising;

zero or more optical emitters;

zero or more photodetectors;

zero or more monitor photodetectors;

electronics for driving the optical emitters;

electronics for receiving signals from the photodetectors;

optics for coupling light into the optical fibers from the optical emitters; and

optics for coupling light from the optical fibers to the photodetectors;

interface electronics for interfacing between electrical data at the electrical connector and the electronics for driving the optical emitters and/or receiving signals from the photodetectors;

power regulation electronics; and

control electronics;

electrical connections from the electrical connector to the boards;

optical connections and electrical connections from the cable to the boards; and

an enclosure containing the boards and the optical connections and electrical connections;

wherein one or more of the following functions is performed;

optical transmission of two or more types of data over independent optical channels;

health and status monitoring, built-in test or firmware upgrades for the first end and the second end of the active optical cable that can be accessed from the first end or the second end of the active optical cable;

transmission of electrical power over the active optical cable wherein the electrical power is used for the modules at the first end and the second end of the active optical cable where voltage regulation or filtering is implemented;

simultaneous transmission of electrical power, optical data, and electrical data over the active optical cable; and

simultaneous optical transmission of both data and power over the active optical cable.

2. The apparatus of claim 1 wherein the optical fibers in the cable are multimode optical fibers, single-mode optical fibers, or multi-core optical fibers.

3. The apparatus of claim 1 wherein data is routed over more than one optical channel simultaneously.

4. The apparatus of claim 1 wherein the electrical conductors in the cable are twisted pairs, coaxial cables, individual conductors, and/or multi-conductor cable assemblies.

5. The apparatus of claim 1 wherein the electrical conductors in the cable transmit data or distribute power.

6. The apparatus of claim 1 wherein the electrical conductors in the cable are configured with a diameter sufficient to carry the required electrical power over the length of the active optical cable.

7. The apparatus of claim 1 further comprising:

shielding on the electrical conductors in the cable.

8. The apparatus of claim 1 wherein the cable further comprises jacketing material, a strength member, or a flexible conduit.

9. The apparatus of claim 1 wherein the electrical connector is a ruggedized connector, a blind-mateable connector, a MIL-DTL-38999 type connector, a D-sub type connector or is hermetically sealed.

10. The apparatus of claim 1 wherein the electrical connector is designed for immersion in water when mated.

11. The apparatus of claim 1 wherein the electrical connector has different size pins to accommodate different current requirements, coaxial pins for high-speed data transmission or filters on the pins for noise and/or electromagnetic interference reduction.

12. The apparatus of claim 1 wherein the boards are printed circuit boards, ceramic boards or a flex circuit.

13. The apparatus of claim 1 wherein the optical emitters are light-emitting diodes (LEDs), Fabry-Perot lasers, Distributed Feedback (DFB) lasers, vertical-cavity surface-emitting lasers (VCSELs), top-emitting VCSELs, bottom-emitting VCSELs or high-power lasers used for power distribution to the other end of the active optical cable.

14. The apparatus of claim 1 wherein the optical emitters have high linearity for analog data transmission.

15. The apparatus of claim 1 wherein the optical emitters are integrated using flip-chip bonding or die placement and wire bonding.

16. The apparatus of claim 1 wherein the photodetectors are p-i-n photodetectors, semiconductor-metal (MSM) photodetectors, avalanche photodetectors, traveling wave photodetectors or resonant cavity photodetectors.

17. The apparatus of claim 1 wherein the photodetectors are integrated using flip-chip bonding or die placement and wire bonding.

18. The apparatus of claim 1 wherein the optical emitters are integrated into TO-cans.

19. The apparatus of claim 1 wherein the photodetectors, the optical emitters or the monitor photodetectors are integrated into TO-cans.

20. The apparatus of claim 1 wherein the optical emitters and the photodetectors are integrated on a submount or an optical bench.

21. The apparatus of claim 20 wherein the optical bench has integrated monitor photodetectors.

22. The apparatus of claim 1 wherein the electronics for driving the light emitters comprise a laser diode driver (LDD).

23. The apparatus of claim 1 wherein the light emitters are directly modulated.

24. The apparatus of claim 1 wherein the light emitters are modulated using an electro-absorption modulator.

25. The apparatus of claim 1 wherein the electronics for receiving signals from the photodetectors comprise a transimpedance amplifier.

26. The apparatus of claim 1 wherein the electronics for receiving signals from the photodetectors comprise a transimpedance amplifier (TIA) followed by a limiting amplifier (LA).

27. The apparatus of claim 1 wherein the optics for coupling light into the optical fibers from the optical emitters comprise an LC ferrule with a lens.

28. The apparatus of claim 1 wherein the optics for coupling light from the optical fibers to the photodetectors comprise an LC ferrule with a lens.

29. The apparatus of claim 1 wherein the optics for coupling light into the optical fibers from the optical emitters and the optics for coupling light from the optical fibers to the photodetectors comprise an optical block.

30. The apparatus of claim 29 wherein the optical block comprises a turning mirror or lenses for coupling the light into and out of the optical fibers.

31. The apparatus of claim 29 wherein the optical block is injection molded.

32. The apparatus of claim 29 wherein the optical block is comprised of ULTEM.

33. The apparatus of claim 29 wherein the optical block is designed to interface with a fiber ribbon.

34. The apparatus of claim 29 wherein the optical block is terminated with optical fibers.

35. The apparatus of claim 34 wherein the optical fibers are terminated on one end with the optical block and on the other end by a MT type ferrule or connector.

36. The apparatus of claim 1 wherein the interface electronics interfaces with 10/100/1000 BaseT Tx Ethernet, transistor-transistor-logic (TTL), CMOS logic, RS-422, RS-485, RS-232, MIL-STD-1553, ARINC-429, an I2C two wire interface, a CAN Bus, FireWire, USB, serial digital interface (SDI), CameraLink, digital visual interface (DVI), HDMI, FibreChannel, Serial RapidIO, electrical interlocks, low latency control signals, analog sensors, analog servos, analog actuators, analog commutation devices or electrical motor controls.

37. The apparatus of claim 1 further comprising:

a SERDES in the interface electronics.

38. The apparatus of claim 37 wherein the SERDES is implemented using a field programmable gate array (FPGA).

39. The apparatus of claim 1 wherein the interface electronics are modular and interchangeable to implement interfaces with different electrical data types without changing other parts of the active optical cable.

40. The apparatus of claim 1 wherein the power regulation electronics support operation over a range of voltages significantly exceeding typical variations (+10%) for a voltage supply.

41. The apparatus of claim 1 wherein the power regulation electronics comprise passive filtering or a voltage regulator.

42. The apparatus of claim 1 wherein the power regulation electronics provide power to the optoelectronic modules at one or more voltage levels.

43. The apparatus of claim 1 wherein the power regulation electronics include one or more electrical paths to one or more electrical conductors on the cable.

44. The apparatus of claim 1 wherein the power regulation electronics enable power distribution across the cable.

45. The apparatus of claim 1 wherein the power regulation electronics provide power for components outside the active optical cable.

46. The apparatus of claim 1 wherein the power regulation electronics filter power or regulate power for components outside the active optical cable.

47. The apparatus of claim 1 wherein the power regulation electronics provide power for components outside the active optical cable at more than one voltage level.

48. The apparatus of claim 1 wherein the control electronics implement temperature compensation.

49. The apparatus of claim 48 wherein the temperature compensation adjusts the optical emitter bias current, the optical emitter modulation current or the optical emitter current peaking

50. The apparatus of claim 1 wherein the control electronics monitor the optical power emitted by the optical emitters using the photocurrent from the monitor photodetectors, the optical power received by the photodetectors using the photocurrent from the monitor photodetectors, adjust the voltage supplied to the interface electronics, adjust the voltage supplied to the electronics for driving the optical emitters, the electronics for receiving signals from the photodetectors or the control electronics, establish a data link between the optoelectronic modules on each end of the active optical cable, enable firmware upgrades to the optoelectronic modules on either end of the active optical cable from the electrical connector on either end of the active optical cable, implement built-in test functionality, route data to an alternative optical channel when a primary channel is degraded or non-functional, communicate outside the active optical cable via communication through pins in the electrical connector or implement health and status monitoring.

51. The apparatus of claim 50 wherein the data link is established electrically or optically.

52. The apparatus of claim 50 wherein the built-in test functionality can detect degradation in components in the optoelectronic modules or in the optical emitters.

53. The apparatus of claim 52 wherein the degradation in the optical emitters is detected using the monitor photodetectors.

54. The apparatus of claim 52 wherein degradation in the optical receiver of an optical link is detected using the monitor photodetectors for the optical emitter and the photodetector for that optical link.

55. The apparatus of claim 50 wherein the built-in test functionality implements optical time domain reflectometry (OTDR) or transmits data generated in the active optical cable to verify correct operation of the active optical cable.

56. The apparatus of claim 50 wherein the health and status monitoring comprises reporting temperatures in the optoelectronic modules, reporting incoming supply voltage levels, reporting flags for voltage ranges outside tolerances, reporting optical emitter degradation, reporting health and status information from the interface electronics, reporting optical channels that are non-functional, reporting optical channels that are functional but degraded to a level requiring replacement of the active optical cable, reporting health information for a component or a system not part of the active optical cable or reporting information about cable health.

57. The apparatus of claim 56 wherein the cable health comprises a break in the optical fibers.

58. The apparatus of claim 57 wherein the location of the break is reported.

59. The apparatus of claim 56 wherein the component not part of the active optical cable is a servo.

60. The apparatus of claim 59 wherein current drawn by the servo is monitored and reported.

61. The apparatus of claim 50 wherein the communication is via a two wire interface, multi-wire interface, or 12C, the communication is with electrical systems on either end of the active optical cable, the communication is performed with test equipment connected to either end of the active optical cable, the communication is performed with equipment used to update firmware in the active optical cable or the communication is performed with test equipment used in development and manufacturing.

62. The apparatus of claim 1 wherein the electrical connections from the electrical connector to the boards accommodate different pin-outs without requiring a change in the boards.

63. The apparatus of claim 1 wherein the electrical connections from the electrical connector to the boards comprise flex circuits, a board edge connector, a cable-to-board connector, an electrical board connector or optical and electrical connectors.

64. The apparatus of claim 1 wherein the electrical connections from the electrical connector to the boards use more than one set of the electrical connections going to more than one board.

65. The apparatus of claim 1 wherein the enclosure comprises a strain relief boot for the cable or a strength member connection for the cable.

66. The apparatus of claim 1 wherein the enclosure protects the boards and the optical and electrical connections from environmental contamination wherein the environmental contamination comprise dust, humidity, salt, fuel, diesel, gasoline, jet fuel, ice, water, solvents, isopropyl alcohol, acetone, hydraulic fluid or deicing fluid.

67. The apparatus of claim 1 wherein the enclosure is conductive, grounded, hermetically sealed, ruggedizes the optoelectronic modules at each end of the active optical cable or provides protection for the boards, the optical connectors and the electrical connections from electromagnetic interference.

68. The apparatus of claim 1 wherein the enclosure comprises a backshell.

69. The apparatus of claim 1 wherein the enclosure comprises an overmolding.

70. The apparatus of claim 1 wherein the enclosure comprises a combination of a backshell and an overmolding or a combination of a backshell and a strain relief boot.

71. A method for implementing a multi-function active optical cable having modules at a first end and a second end, the method comprising:

optically transmitting two or more types of data over independent optical channels on the active optical cable; and

transmitting electrical power over the active optical cable and using the electrical power for modules at the first end and the second end of the active optical cable where voltage regulation or filtering is implemented.

72. The method of claim 71 further comprising:

simultaneously transmitting electrical power, optical data and electrical data over the active optical cable.

73. The method of claim 71 further comprising:

performing operations of health and status monitoring, built-in test or firmware upgrades for the first end and the second end of the active optical cable wherein the operations are accessed from the first end or the second end of the active optical cable.

74. The method of claim 71 further comprising:

simultaneously performing optical transmission of both data and power over the active optical cable.