Thermal sensing fiber devices

• US 7,567,740 B2
• Filed: 09/28/2006
• Issued: 07/28/2009
• Est. Priority Date: 07/14/2003
• Status: Active Grant

• Current Assignee: Massachusetts Institute of Technology
• Original Assignee: Massachusetts Institute of Technology
• Inventors: Joannopoulos, John D., Shapira, Ofer, Fink, Yoel, Abouraddy, Ayman F., Bayindir, Mehmet, Arnold, Jerimy R., Sorin, Fabien
• Primary Examiner(s): Connelly Cushwa; Michelle R
• Assistant Examiner(s): Peace; Rhonda S
• Application Number:
  US11/529,111
• Publication Number:
  US 20090097805A1
• Time in Patent Office: 1,034 Days
• Field of Search: 385/12, 385/100, 385/101
• US Class Current: 385/101
• CPC Class Codes: B29D 11/00663 Production of light guides
• CPC Class Codes: C03B 2201/86 Chalcogenide glasses, i.e. S, Se or Te glasses
• CPC Class Codes: C03B 37/01222 for making preforms of multiple core optical fibres preforms of multifibres C03B37/01214
• CPC Class Codes: C03B 37/026 Drawing fibres reinforced with a metal wire or with other non-glass material
• CPC Class Codes: C03C 13/00 Fibre or filament compositions manufacture of fibres or filaments C03B37/00
• CPC Class Codes: C03C 13/003 Conducting or semi-conducting fibres
• CPC Class Codes: C03C 13/043 Chalcogenide glass compositions
• CPC Class Codes: C03C 25/54 Combinations of one or more coatings containing organic materials only with one or more coatings containing inorganic materials only
• CPC Class Codes: G02B 6/02 Optical fibres with cladding with or without a coating
• CPC Class Codes: G02B 6/02304 Core having lower refractive index than cladding, e.g. air filled, hollow core
• CPC Class Codes: G02B 6/02328 Hollow or gas filled core
• CPC Class Codes: G02B 6/02361 Longitudinal structures forming multiple layers around the core, e.g. arranged in multiple rings with each ring having longitudinal elements at substantially the same radial distance from the core, having rotational symmetry about the fibre axis
• CPC Class Codes: G02B 6/02366 Single ring of structures, e.g. "air clad"
• CPC Class Codes: G02B 6/02371 Cross section of longitudinal structures is non-circular
• CPC Class Codes: H01L 31/09 Devices sensitive to infrared, visible or ultraviolet radiation H01L31/101 takes precedence

Abstract

There is provided a thermal sensing fiber including a semiconducting element having a fiber length and characterized by a bandgap energy corresponding to a selected operational temperature range for the fiber in which there can be produced a change in thermally-excited electronic charge carrier population in the semiconducting element in response to a temperature change in the selected temperature range. At least one pair of conducting electrodes is provided in contact with the semiconducting element along the fiber length, and an insulator is provided along the fiber length.

Claims

1. A thermal sensing fiber comprising:

a semiconducting element having a fiber length and characterized by a bandgap energy sufficient to produce a measurable change in thermally-excited electronic charge carrier population in the semiconducting element in response to a temperature change in an operational temperature range of the fiber;

at least one pair of conducting electrodes in contact with the semiconducting element along the fiber length; and

an insulator along the fiber length, wherein the semiconducting element, electrodes, and insulator are each characterized by a viscosity that is less than about 10⁶ Poise while substantially maintaining structural material integrity, at a common temperature.

2. The thermal sensing fiber of claim 1 wherein the semiconducting element is characterized as a non-crystalline material.

3. The thermal sensing fiber of claim 2 wherein the semiconducting element is amorphous.

4. The thermal sensing fiber of claim 3 wherein the semiconducting element is glassy.

5. A thermal sensing fiber comprising:

a semiconducting element having a fiber length and characterized by a bandgap energy sufficient to produce a measurable change in thermally-excited electronic charge carrier population in the semiconducting element in response to a temperature change in an operational temperature range of the fiber;

at least one pair of conducting electrodes in contact with the semiconducting element along the fiber length; and

an insulator along the fiber length, wherein the semiconducting element, electrodes, and insulator are each characterized by a viscosity that is less than about 10⁶ Poise while substantially maintaining individual material properties, at a common temperature.

6. The thermal sensing fiber of claim 5 wherein the common temperature is a fiber draw temperature.

7. The thermal sensing fiber of claim 5 wherein the semiconducting element, electrodes, and insulator are each characterized by a viscosity that is less than about 10⁶ Poise while substantially maintaining individual material properties and without material decomposition, at a common temperature.

8. The thermal sensing fiber of claim 5 wherein the semiconducting element, electrodes, and insulator are each characterized by a viscosity that is no greater than about 10⁵ Poise.

9. The thermal sensing fiber of claim 5 wherein one of the semiconducting element, electrodes, and insulator is also characterized by a viscosity that is greater than about 10⁴ Poise.

10. The thermal sensing fiber of claim 5 wherein a one of the semiconducting element, electrodes, and insulator that constitutes a majority volume of material of the fiber is also characterized by a viscosity that is greater than about 10⁴ Poise.

11. The thermal sensing fiber of claim 5 wherein the fiber is capable of supporting a mechanical load of at least about 100 grams of force applied to a longitudinal axis of the fiber at the common temperature.

12. A thermal sensing fiber comprising:

a semiconducting element having a fiber length and characterized by a band gap energy sufficient to produce a measurable change in thermally-excited electronic charge carrier population in the semiconducting element in response to a temperature change in an operational temperature range of the fiber;

at least one pair of conducting electrodes in contact with the semiconducting element along the fiber length; and

an insulator along the fiber length, wherein the semiconducting element, electrodes, and insulator are disposed in a geometric relationship corresponding to a drawing preform of the fiber.

13. A thermal sensing fiber comprising:

A semiconducting element comprising a semiconducting chalcogenide glass selected from the group consisting of Ge_xAs_40-xSe_yTe_60-y, where 10<

x<

20 and 10<

y<

15;

As₂S₃; and

As₄₀Se_60-xTe_x, the semiconducting element having a fiber length and being characterized by a band gap energy sufficient to produce a measurable change in thermally-excited electronic charge carrier population in the semiconducting element in response to a temperature change in an operational temperature range of the fiber;

at least one pair of conducting electrodes in contact with the semiconducting element along the fiber length; and

an insulator along the fiber length.

14. The thermal sensing fiber of claim 13 wherein the semiconducting element is characterized as a non-composite material.

15. The thermal sensing fiber of claim 13 wherein the semiconducting element is characterized as a non-particulate material.

16. The thermal sensing fiber of claim 13 wherein the semiconducting element is homogeneous along at least one fiber direction.

17. The thermal sensing fiber of claim 13 wherein the semiconducting element is characterized as an inorganic material.

18. The thermal sensing fiber of claim 13 wherein the semiconducting element bandgap energy is less than about 2 eV.

19. The thermal sensing fiber of claim 18 wherein the semiconducting element bandgap energy is less than about 1.5 eV.

20. The thermal sensing fiber of claim 19 wherein the semiconducting element bandgap energy is less than about 1 eV.

21. The thermal sensing fiber of claim 13 wherein the semiconducting element is characterized by a thermal activation energy that is no greater than about 0.5 eV.

22. The thermal sensing fiber of claim 13 wherein the semiconducting element bandgap energy is on the order of k_B T₀, where k_B is Boltzmann constant and T₀ is a reference temperature in the selected operational temperature range for the fiber.

23. The thermal sensing fiber of claim 22 wherein the reference temperature T₀ is about 37°

C.

24. The thermal sensing fiber of claim 13 wherein the semiconducting element comprises a solid semiconducting rod.

25. The thermal sensing fiber of claim 13 wherein the semiconducting element comprises a hollow semiconducting rod.

26. The thermal sensing fiber of claim 13 wherein the semiconducting element comprises a bulk semiconducting element.

27. The thermal sensing fiber of claim 13 wherein the semiconducting element comprises a solid semiconducting fiber core.

28. The thermal sensing fiber of claim 13 wherein the semiconducting element comprises a hollow semiconducting fiber core.

29. The thermal sensing fiber of claim 13 wherein the semiconducting element comprises a semiconducting layer.

30. The fiber photodetector of claim 29 wherein the semiconducting element comprises a circumferential semiconducting layer.

31. The thermal sensing fiber of claim 13 wherein the semiconducting element comprises a plurality of semiconducting elements, each semiconducting element in contact with at least one pair of conducting electrodes along the fiber length.

32. The thermal sensing fiber of claim 31 wherein each semiconducting element is characterized by a distinct bandgap energy corresponding to a selected distinct operational temperature range for the fiber in which there can be produced a change in thermally-excited electronic charge carrier population in that semiconducting element in response to a temperature change in the selected distinct temperature range.

33. The thermal sensing fiber of claim 13 wherein the chalcogenide glass comprises be Ge₁₇As₂₃Se₁₄Te₄₆.

34. The thermal sensing fiber of claim 13 wherein the insulator comprises a polymeric insulating material.

35. The thermal sensing fiber of claim 34 wherein the polymeric insulating material comprises a high glass-transition-temperature material.

36. The thermal sensing fiber of claim 34 wherein the polymeric insulating material comprises poly-ether imide.

37. The thermal sensing fiber of claim 34 wherein the polymeric insulating material comprises poly-ether sulfone.

38. The thermal sensing fiber of claim 34 wherein the polymeric insulating material comprises poly-methyl methacrylate.

39. The thermal sensing fiber of claim 34 wherein the polymeric insulating material comprises a polymeric layer.

40. The thermal sensing fiber of claim 13 wherein the insulator is a circumferential protective fiber layer disposed at an outer surface of the fiber.

41. The thermal sensing fiber of claim 13 wherein the conducting electrodes comprise metal electrodes.

42. The thermal sensing fiber of claim 13 wherein the conducting electrodes comprise metal alloy electrodes.

43. The thermal sensing fiber of claim 13 wherein the conducting electrodes comprise Sn electrodes.

44. The thermal sensing fiber of claim 13 wherein the conducting electrodes comprise Sn—

Ag electrodes.

45. The thermal sensing fiber of claim 13 wherein the conducting electrodes of each electrode pair are connected in an electronic circuit to apply a bias voltage to the semiconducting element of the fiber.

46. The thermal sensing fiber of claim 45 wherein the electronic circuit is configured to measure an indication of thermally-excited electronic charge carriers produced by the semiconducting element of the fiber.

47. The thermal sensing fiber of claim 46 wherein the electronic circuit is configured to measure current as an indication of thermally-excited electronic charge carriers produced by the semiconducting element of the fiber.

48. The thermal sensing fiber of claim 46 wherein the thermal sensing circuit is configured to measure capacitance as an indication of thermally-excited electronic charge carriers produced by the semiconducting element of the fiber.

49. The thermal sensing fiber of claim 46 wherein the electronic circuit is configured to measure voltage across a resistive circuit element as an indication of thermally-excited electronic charge carriers produced by the semiconducting element of the fiber.

50. The thermal sensing fiber of claim 13 wherein the at least one pair of conducting electrodes comprises a plurality of pairs of conducting electrodes.

51. The thermal sensing fiber of claim 13 wherein each conducting electrode is geometrically confined by the semiconducting element and the insulator.

52. The thermal sensing fiber of claim 13 further comprising an optical transmission element.

53. The thermal sensing fiber of claim 13 wherein the fiber length is greater than about 10 meters.

54. The thermal sensing fiber of claim 53 wherein the fiber length is greater than about 20 meters.

55. The thermal sensing fiber of claim 54 wherein the fiber length is greater than about 50 meters.

56. The thermal sensing of claim 55 wherein the fiber length is greater than about 100 meters.

57. A thermal sensing fiber comprising:

an optical transmission element having a fiber length;

at least one metal-semiconductor-metal thermal sensing element along the fiber length; and

an insulator along the fiber length;

the optical transmission element, thermal sensing element, and insulator each characterized by a viscosity that is less than about 10⁶ Poise while substantially maintaining individual material properties, at a common temperature.

58. The thermal sensing fiber of claim 57 wherein the optical transmission element comprises a hollow core optical transmission element.

59. The thermal sensing fiber of claim 58 wherein the hollow core transmission element comprises a hollow-core photonic bandgap waveguide.

60. The thermal sensing fiber of claim 57 wherein the optical transmission element comprises a solid core optical transmission element.

61. The thermal sensing fiber of claim 57 wherein the optical transmission element comprises a bulk optical transmission element disposed at a non-central fiber position in a cross-section of the fiber.

62. The thermal sensing fiber of claim 57 wherein the metal-semiconductor-metal thermal sensing element is disposed radially outward of the optical transmission element in a cross-section of the fiber.

63. The thermal sensing fiber of claim 57 wherein the metal-semiconductor-metal thermal sensing element is disposed radially inward of the optical transmission element in a cross-section of the fiber.

64. A self-heat-monitoring fiber comprising:

an insulator having a fiber length; and

at least one metal-semiconductor-metal thermal sensing element along the fiber length and disposed at a position in a cross section of the fiber for sensing changes in temperature of the fiber;

the insulator and thermal sensing element each characterized by a viscosity that is less than about 10⁶ Poise while substantially maintaining individual material properties at a common temperature.

65. The self-heat-monitoring fiber of claim 64 further comprising an optical transmission element, and wherein the metal-semiconductor-metal thermal sensing element is disposed in the fiber cross section relative to the optical transmission element for sensing changes in temperature of the fiber caused by power dissipation from the optical transmission element.