title: Reversible photo-induced long-period fiber gratings in photonic liquid crystal fibers.
abstract: A novel light-controllable long-period fiber grating (LPFG) is demonstrated by making use of a PCF infiltrated with a photoresponsive liquid crystal (LC) mixture consisting of nematic LC molecules and light-sensitive 4-methoxyazobenzene (4MAB). With the aid of the photo-induced isomerization of 4MAB, the refractive index of the LC mixture can be modulated and the periodic index perturbation along the fiber can be achieved by exposing the PCF to a blue laser through a mask. The resonance wavelength and dip depth of the LPFG can be controlled by using different blue-laser irradiation time, numbers of period, and 4MAB concentrations. In addition, the photo-induced LPFG is erasable under green-laser illumination.
authors: Department of Photonics, Institute of Electro-optical Engineering, National Sun Yat-Sen University, Kaohsiung, Taiwan.
authors: Jia-hong
authors: JH
authors: Liou
authors: Tin-hao
authors: TH
authors: Chang
authors: Ta
authors: T
authors: Lin
authors: Chin-ping
authors: CP
authors: Yu
mesh_terms: D004867:Equipment Design; D019544:Equipment Failure Analysis; D005336:Fiber Optic Technology / Q000295:instrumentation*; D050866:Liquid Crystals / Q000737:chemistry* / Q000528:radiation effects; D017785:Photons; D012031:Refractometry / Q000295:instrumentation*