Fabrication of composite optical fiber taper through “click” polymerization initiated by evanescent field for sensing

In this work, evanescent field initiated “click” polymerization on the surface of the waveguide is used to fabricate composite optical fiber taper probe for sensing. This improvement can effectively keep the polymerization within the scale of evanescent field on the surface of the fiber taper and prevent it in the precursor solution. Besides, for special sensing requirements, such as sensing target and sensitivity, this novel approach (photo-plating) is convenient to choose ingredients composed of the precursor solution in fabrication of a corresponding composite fiber taper probe. The photo-plating process usually completes within 30 s in specific precursor solution. As an example, a probe with a fluorescent polymer film composed of meso-tetrakis(4-allyloxyphenyl) porphyrin (TAOP) was made, which provides the binding sites for the nitro-based explosive molecules. The results indicate that the probe exhibits a good sensitivity and repeatability to trinitrotoluene (TNT), providing a fiber probe platform with miniaturization, real-time and remote monitoring for the detection of TNT vapor.