Tapered fibre liquid crystal optical device

The paper presents the results of design, manufacturing and characterization of an hybrid broad band in-line device using a nematic liquid crystal as an active medium which influences light propagating in a biconical optical fibre taper. A liquid crystal mixture denoted 6CHBT* and E7 is designed for electric, as well as temperature control of electromagnetic wave propagation in a broad wavelength range. The main reason of using the taper structure with a waist of 10 +/- 0.5 mu m and losses lower than 0.5 dB is possibility of using a liquid crystalline medium as cladding. Such approach enables effective control of its refractive index. Two kinds of initial liquid crustal molecules' orientation (parallel and orthogonal) in relation to the light beam propagating in a taper were applied. Performance of a tuned cladding was studied at electric field of the range of 0V - 160V in the room temperature equal to 20 degrees C. Influence of induced reorientation of liquid crystal molecules was measured at a broad wavelength range [500-1700 nm].