Title :
Tunable photonic crystal waveguide coupler with nematic liquid crystals
Author :
Liu, Chen-Yang ; Chen, Lien-Wen
Author_Institution :
Dept. of Mech. Eng., Nat. Cheng Kung Univ., Tainan, Taiwan
Abstract :
Photonic crystals (PCs) have great potential in applications for their ability to control lightwave propagation and the possibilities of implementing PC-based optical waveguide into waveguide coupler systems. In this letter, the novel tunable PC waveguide coupler based on nematic liquid crystals is proposed, and its coupling properties are numerically investigated by using the finite-difference time-domain method. The coupling length of PC waveguide couplers with liquid crystals is shorter than the coupling length of coupler without liquid crystals at the same input wavelength. The refractive indexes of liquid crystals can be changed by rotating the directors of liquid crystals. Then, we can control the direction of light propagation in PC waveguide coupler. These results may provide novel application of switching devices in optical circuits.
Keywords :
finite difference time-domain analysis; liquid crystal devices; nematic liquid crystals; optical control; optical couplers; optical materials; optical waveguides; photonic crystals; refractive index; PC-based optical waveguide; coupling properties; finite-difference time-domain method; infiltration; nematic liquid crystals; optical circuits; photonic crystals; refractive index; switching devices; tunable PC waveguide coupler; tunable photonic crystal waveguide coupler; waveguide coupler system; Lighting control; Liquid crystals; Liquid waveguides; Optical coupling; Optical propagation; Optical refraction; Optical variables control; Optical waveguides; Photonic crystals; Tunable circuits and devices;
Journal_Title :
Photonics Technology Letters, IEEE
DOI :
10.1109/LPT.2004.831267
