The present work has been centered in the design, fabrication and characterization of a new in-line tunable nematic liquid crystal (TNLC) optical fiber device. The main reason of using a biconical optical fibre taper as a core surrounded by liquid crystals molecules is the possibility to change the losses by the electrically induced reorientation of liquid crystal molecules in a broad wavelength range. A taper is made from a standard single mode telecommunication fiber SMF28®, whereas the clad uses the nematic mixture 1550C1 type. A supercontinnum source with a bandwidth of [500–700 nm] and laser with wavelength 532 nm were used as light sources.