Fabrication of polymer Fabry-Perot fiber sensors using optical fiber microheaters

We report on a novel fabrication technique for polymer based Fabry-Perot (F-P) optical fiber sensors. The F-P interferometers are based on microbubbles generated in the polymer by means of a microheater fiber probe. Upon inserting the probe and a cleaved single-mode fiber in a capillary tube containing the polymer, a microbubble can be readily generated which can serve as a reflective surface. A F-P cavity is thus formed by the microbubble and the single-mode fiber tip and temperature or strain deforming the bubble can be detected upon monitoring the FP resonances. The fabrication and performance of these devices as a temperature sensor is presented in this paper.