High-sensitivity temperature sensor using a side-polished single-mode fiber covered with the polymer planar waveguide

A temperature sensor based on evanescent field coupling between a single-mode side-polished fiber and a polymer planar waveguide was demonstrated. Due to thermooptic effects of a polymer planar waveguide, the resonance wavelength of the device is very sensitive to ambient temperature. Two kinds of polymers were used as planar waveguide materials. Fabricated sensors have a sensitivity of -0.37 nm//spl deg/C and -0.71 nm//spl deg/C, respectively. We also measured the thermooptic coefficient of employed polymer approximately.