Polymer Optical Fiber Strain Senor Based on Whispering Gallery Modes

This paper reports and experimentally demonstrates a strain sensor based on whispering gallery modes (WGMs) effect in a polymer step-index optical fiber. Excitation of WGMs in polymer optical fiber (POF) is achieved by evanescent coupling with a silica fiber taper. The tensile strain to a short section of a polymer fiber is applied by axial elongation. Our results show that the proposed WGM stain sensor can measure strains up to 6666 µεwith a strain sensitivity of 0.49 pm/ µε.