Polymer Microtips Fabricated at the Extremity of Photonic Crystal Fibers

In this paper, a simple method of manufacturing micrometer-sized polymer elements （microtips） at the extremities of the photonic crystal fibers （PCFs）, which are replacing standard optical fibers in many applications due to their unique properties, is presented. The method of microtips fabrication is based on the phenomena of photopolymerization, which is successfully used by the first time, to be best of our knowledge, to manufacture microtip at PCF. The three component photopolymerizable formulation consists of photo-initiating system and multifunctional triacrylate. The photopolymerization is carried out by green laser with the microtip growth controlled by the light exposure parameters （i.e. power and time）. Results of mic：rotip fabrication on standard fiber （SMF-28e＋） and large mode area PCF （LMA-10） are provided. Theinfluence of the initial process parameters on the final microtip characteristics （i.e., length, diameter and profile） is discussed. The potential applications of such polymer microtips are near-field scanning optical microscopy, coupling light sources with fibers and sensing.