Environmentally Sensitive Optical Fibers and Waveguides Based on Hydrogen-Bonding Compounds

Novel optical fibers and waveguides were designed and created from blends of hydrogen bonding compounds ( polyvinyl alcohol, polyvinylpyridine, acrylic acid ) with glassy polymers and low molar mass liquid crystals. Optical fibers display significant birefringence in their cores since the drawing procedure of the fibers lead to the higher concentration and orientation of liquid crystal inside the core of the fiber. The fibers were studied by differential scanning calorimetry and optical methods. It was shown that fibers gain additional stability if they are physically crosslinked with diacidic low molar mass compounds ( sebacic acid ). Optical response of the fibers (changes in propagating light intensity or additional leakage of light) to the action of volatile organic compounds (VOCs) was studied and discussed for different types of polar and non-polar VOCs. It was found that optical response depends on structural reorganization of the fibers that starts in the outer layer and then propagates towards the core in a way similar to the response of liquid crystals [1]
[1] Rebirth of liquid crystals for sensoric applications: environmental and gas sensors
PV Shibaev, M Wenzlick, J Murray, A Tantillo, J Howard-Jennings
Advances in Condensed Matter Physics 2015