Tapered fiber optic devices with liquid crystal cladding

Abstract

The paper presents the results of manufacturing and characterization of a broad band in-line hybrid device using a nematic liquid crystal as an active cladding for biconical tapered optical fiber. Two different liquid crystal mixtures denoted as 1550* and E7 were used for electric and temperature control in a broad wavelength range. An optical fiber tapers with a waist of 10±0.5 μm and losses lower than 0.5 dB in a whole broad band spectrum range were applied. Such taper waist diameter makes the whole waist as core for light propagation, where the surrounding air becomes the cladding. Additionally, such diameter enables an effective control of molecules orientation. Performance of a tuned cladding was studied in an electric field in the range between 0 V and 160 V in the room temperature equal to 20 °C. Influence of induced liquid crystal molecules reorientation was measured at a broad wavelength range (500-1700 nm).