Design of tunable bandgap guidance in high-index filled microstructure fibers

Abstract

Tunable photonic bandgap (PBG) microstructure fibers, which were filled nematic liquid crystals (NLC), were theoretically investigated based on bandgap theory. By means of the modified plane-wave method, it is found that PBGs shift to the longer wavelength with increasing refractive index of NLC [ny(θ)] for y-polarized light. Fundamental modes are found in these PBG reigns, whose effective mode area, leakage loss and group velocity dispersion (GVD) have been calculated by using the full-vector finite-element method with anisotropic perfectly matched layers. The mode fields become larger with the increase of ny(θ), whereas the leakage loss varies slightly. Moreover, GVD is strongly dependent on ny(θ) and wavelength, which is much larger than the material dispersion of silica.