Electro-Steering Tapered Fiber-Optic Device with Liquid Crystal Cladding

Abstract

The paper presents the results of design, manufacturing, and characterization of a hybrid broad band in-line fiber-optic device. It uses nematic liquid crystal as cladding with electro-steering properties in a biconical optical fiber taper structure. Liquid crystal mixtures denoted as 6CHBT and E7 are designed for electric as well as temperature control of electromagnetic wave propagation in a broad wavelength range. The applied taper with 10±0.5 μm diameters has losses lower than 0.5 dB in whole investigated spectrum range. Three kinds of initial liquid crystal molecules’ orientations (parallel, orthogonal, and twist) in relation to the light beam propagating in a taper were applied. The performance of a tuned cladding was studied at an electric field of the range of 0–190 V and the temperature range from 20°C up to 42°C and 59°C for 6CHBT and E7, respectively. The induced reorientation of liquid crystal molecules was measured at a broad wavelength range (550-1550 nm).

SPR Sensor Based on a Tapered Optical Fiber with a Low Refractive Index Liquid Crystal Cladding and Bimetallic Ag–Au Layers

“…Based on the data obtained for TOF w/o metallic film measured in air, and TOF with the cover (also in the air), it can be observed that the bimetallic cover of Au/Ag causes attenuation with a value similar to the silver layers [ 39 ]. As before, the main dips (A) are shifted from the peaks obtained for single metallic layers and are equal to 803.6 nm, = 926.4 nm, and = 968.4 nm for orthogonal, parallel, and twist, respectively.…”

“…In the case of the orthogonal cell, the absorption is the lowest and is approximately 60%. High power fluctuations are visible on the presented relations, but they are slightly lower than in the case of the single metal cover [ 14 , 39 ]. This is probably due to the deposition of a thinner metallic film, in particular the silver one ( h Ag ~ 5 nm).…”

Research on Optical Properties of Tapered Optical Fibers with Liquid Crystal Cladding Doped with Gold Nanoparticles

“…Additionally, the special anti-gravity unit is used because during the elongation process the fiber position is reduced. The signal increase in the anti-gravity system is an impulse for changing drawing velocity, as well as lowering the burner position [11,12]. Additionally, by selection of a proper flame, we can make a taper with a very small dimension of the taper waist.…”

“…This parameter is described as [9]:From the above formula, it can be concluded that the number of modes propagating in the fiber is also influenced by the wavelength λ and the diameter of the core a. This parameter is important when we want to use a tapered optical fiber [10][11][12] or long period gratings (LPG) [13,14] as an element of optical devices. LCs are built of elongated molecules.…”

Temperature effect on the light propagation in a tapered optical fiber with a twisted nematic liquid crystal cladding

“…A low losses structure is obtained for an adiabatic taper characterized by a long transition region compared to the taper waist region [2]. Since a light beam is propagated in the whole structure of a taper waist without division into core and cladding, hence it is possible to influence beam propagation inside the fiber by boundary conditions modification [3]. In a structure created in this way, the taper waist region becomes the core and the surrounding medium becomes its cladding.…”