Temperature sensor based on Ge-doped microstructured fibers

The fundamental mode cutoff properties of Ge-doped microstructured fibers, filled with a liquid, permit the implementation of wavelength- and amplitude-encoded temperature sensors with an ultra-high sensitivity. The cutoff wavelength changes with temperature, and the thermo-optic coefficient of the liquid determines the sensitivity of the sensor. Sensitivity as high as 25 nm/◦C is reported. In addition, simple amplitude interrogation techniques can be implemented using the same sensor heads