title: Tunable negative refraction photonic crystals achieved by liquid crystals.
abstract: The photonic crystal with a square lattice of Si cylinders surrounded by nematic liquid crystals is investigated. The directors of the liquid crystal are parallel to the two dimensional PC plane. The transversed electric (TE) modes are studied. The plane wave expansion method is used to calculate the equi-frequency surface (EFS). The negative refraction phenomenon is found and the refractive angle can be tuned by changing the directors of the nematic liquid crystals.
authors.affiliation: Department of Mechanical Engineering, National Cheng Kung University, Tainan, Taiwan.
authors.forename: Yao-Yu
authors.initials: YY
authors.lastname: Wang
authors.forename: Lien-Wen
authors.initials: LW
authors.lastname: Chen