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 [n<sub>y</sub>(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 n<sub>y</sub>(θ), whereas the leakage loss varies slightly. Moreover, GVD is strongly dependent on n<sub>y</sub>(θ) and wavelength, which is much larger than the material dispersion of silica.
© 2006 Optical Society of America
Original Manuscript: April 22, 2005
Revised Manuscript: October 8, 2005
Manuscript Accepted: October 21, 2005
Chunshu Zhang, Guiyun Kai, Zhi Wang, Tingting Sun, Chao Wang, Yange Liu, Jianfei Liu, Weigang Zhang, Shuzhong Yuan, and Xiaoyi Dong, "Design of tunable bandgap guidance in high-index filled microstructure fibers," J. Opt. Soc. Am. B 23, 782-786 (2006)