Thermal sensing fiber devices

1. A feedback-controlled self-heat-monitoring fiber comprising:

an insulator having a fiber length;

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 fiber temperature;

an optical transmission element disposed along the fiber length;

an electronic circuit connected to the thermal sensing element for indicating a change in fiber temperature; and

a controller for controlling optical transmission through the optical transmission element in response to an indication of change in fiber temperature.

2. The fiber of claim 1 wherein the controller is connected to an optical input source for controlling optical transmission input to the optical transmission element.

3. The fiber of claim 2 wherein the controller is connected to the optical input source to control power input to the optical transmission element.

4. The fiber of claim 2 wherein the optical input source comprises a laser.

5. The fiber of claim 1 wherein the wherein the semiconductor comprises a semiconducting chalcogenide glass.

6. The fiber of claim 5 wherein the chalcogenide glass comprises Ge x As 40-x Se y Te 60-y , where 10<x<20 and 10<y<15.

7. The fiber of claim 5 wherein the chalcogenide glass comprises Ge 17 As 23 Se 14 Te 46 .

8. The fiber of claim 1 wherein the semiconductor is characterized by a band gap energy corresponding to a selected operational temperature range for the fiber in which there is produced a change in thermally-excited electronic charge carrier population in the semiconductor in response to a temperature change in the selected temperature range.

9. The fiber of claim 8 wherein the semiconductor band gap energy is on the order of k B T 0 , where k B is Boltzmann constant and T 0 is a reference temperature of about 37° C.

10. The fiber of claim 1 wherein optical transmission element comprises a photonic bandgap waveguide.

11. A method for controlling optical fiber transmission comprising:

inputting an optical signal to an optical transmission element of a fiber having a fiber length;

generating in an electronic circuit an indication of fiber temperature based on an electrical signal produced by a metal-semiconductor-metal thermal sensing device that is disposed along the fiber length, as the optical signal is transmitted along the fiber length; and

controlling input of the optical signal based on the indication of fiber temperature.

12. The method of claim 11 wherein the optical signal comprises a laser signal.

13. The method of claim 11 wherein the optical signal comprises an infrared signal.

14. The method of claim 11 wherein the optical signal comprises a visible-wavelength signal.

15. The method of claim 11 wherein controlling input of the optical signal comprises controlling power of the input optical signal.

16. The method of claim 15 wherein controlling power of the input optical signal comprises reducing power of the input signal.

17. The method of claim 15 wherein controlling power of the input optical signal comprises terminating input of the input signal.

18. The method of claim 15 wherein controlling power of the input optical signal comprises maintaining power of the input signal.

19. The method of claim 11 wherein controlling input of the optical signal is carried out as an optical signal is transmitted along the fiber length during a surgical procedure employing the fiber.

20. The method of claim 19 wherein the surgical procedure comprises endoscopic surgery.