Liquid-crystal-based in-fiber tunable spectral structures

We present new approaches for realizing enhanced tunable filters based on filling special fibers with nematic or cholesteric liquid crystal. One of the suggested approaches is to realize high-resolution longitudinal structure of electrodes using printed circuit board technology and then fill tapered capillaries with the liquid crystal, thus obtaining the desired spectral response at low voltage and with low insertion loss. Another approach is to fill special photonic crystal fibers with liquid crystal and obtain spectral tunability by generating phase differences between light paths.