Liquid Crystal Photonic Crystal Fibers and their applications

Liquid Crystal Photonic Crystal Fibers (LC-PCFs) known also as Photonic Liquid Crystal Fibers (PLCFs) are advanced specialty fibers that benefit from a combination of "passive" photonic crystal fiber host microstructures infiltrated with "active" liquid crystal guest materials and are responsible for a diversity of new and uncommon spectral, propagation, and polarization properties. This combination has simultaneously reinvigorated research in both fields of Liquid Crystals Photonics and Fiber Optics by demonstrating that optical fibers can be more "special" than previously thought. Simultaneously, photonic liquid crystal fibers create a new class of optical waveguides that utilizes unique guiding properties of the micro-structured photonic crystal fibers and attractive tunable properties of liquid crystals. Comparing to the conventional photonic crystal fibers, the photonic liquid crystal fibers can demonstrate greatly improved control over their optical properties. The paper describes basic physics including guiding mechanisms, spectral properties, polarization phenomena, thermal, electrical and optical controlling effects as well as innovative emerging technology behind these developments. Some examples of novel LC-PCFs highly tunable photonic devices as: attenuators, broadband filters, polarizers, waveplates, and phase shifters recently demonstrated at the Warsaw University of Technology are also presented. Current research progress in the field indicates that a new class of emerging liquid crystals tunable photonics devices could be expected.