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-mo de side-polished fiber and a polymer planar waveguide was demonstrated. Due to thermooptic effects of a polymer planar waveguide, the resonance wavele ngth of the device is very sensitive to ambient temperature. Two kinds of p olymers were used as planar waveguide materials. Fabricated sensors have a sensitivity of -0.37 nm/degreesC and -0.71 nm/degreesC, respectively. We al so measured the thermooptic coefficient of employed polymer approximately.