Electrically tunable liquid-crystal photonic crystal fiber

Abstract

Tunable light switch using a photonic crystal fiber filled with nematic liquid crystal is demonstrated. The original band-gap-guiding fiber structure was transformed to a total internal reflection-guiding photonic crystal fiber by filling liquid crystal into the air core and cladding air holes. By applying external voltage to the liquid-crystal-filled fiber, we have demonstrated an electrically tunable fiber-optical switch with over 30dB attenuation at 60Vrms for a He-Ne laser beam. This liquid-crystal-filled photonic crystal fiber will find useful applications in fiber-optic communication systems.

Temperature tuning of polarization mode dispersion in single-core and two-core photonic liquid crystal fibers

“…In this way, the light interaction with such materials as liquid crystals, polymers, water, glycerin, oils and other fluids allows us to obtain tunable PCF devices [11]. In particular, a difference between core and cladding refractive indices can be modified by the external factors such as temperature, electric, magnetic or optical field [6]. This fact leads to the possibility of the bandgap tuning [4] as well as of the switching between two different waveguiding mechanisms governed by total internal reflection (TIR) and photonic band gap (PBG) [7].…”

“…Recently, there has been a great interest in photonic crystals fibers and particularly in more advanced micro-structures known as photonic liquid crystal fibers [4][5][6]. The PLCF consisting of a PCF filled with a LC benefits from a combination of a passive PCF host structure and an "active" LC guest material and are responsible for diversity of new and uncommon properties including also particular polarization properties [7].…”

Tunability of discrete diffraction in photonic liquid crystal fibres

“…Propagation properties of PCFs can be dynamically changed (including switching between different guiding mechanisms) by introducing gaseous, liquid or solid media into the air−channels [1,[11][12][13][14][15][16][17]. This simple idea has been found to be very useful while broadening the applicability of PCFs.…”

“…Specifically, the concept of using liquid crystals (LCs), resulting thus in a new type of optical fibres, has gained significant amount of the scientific attention. These particular photonic structures are often referred to as pho− tonic liquid crystal fibres (PLCFs) [12][13], liquid crys− tal−photonic crystal fibres (LC−PCFs) [14], or liquid crys− tal−photonic bandgap fibres [15]. LCs are anisotropic, and, in most cases, their (averaged) refractive indices are higher than that of silica (glass).…”

Second and Fourth Harmonic Frequencies in Electric Field-Induced Liquid Crystal Reorientations

“…Nematic liquid crystal (LC) has been widely used for amplitude and phase modulations, such as displays [1,2], optical communications [3], adaptive lens [4][5][6][7][8], and tunable photonic devices [9,10]. The applied voltage can be either a square, sinusoidal or saw-tooth wave and the frequency can range from tens to a few kilo-hertz.…”