Long-Period Fiber Gratings with Low-Birefringence Liquid Crystal

The paper presents a long-period fiber grating (LPFG) with a unique liquid crystal (LC) cladding. We report the results of experiments on the LPFG's spectral properties that can be modified by temperature due to the presence of a low-birefringence nematic LC mixture. We also present our latest results concerning the influence of an external electric field on an LPFG with a medium-birefringence LC. The LPFGs are fabricated by using electric arc discharges in two types of fiber: single-mode (SM) fibers and photonic crystal fibers (PCFs). The experimental study is focused on achieving external tuning by adjusting thermal and electric field effects influencing the spectral properties of LPFGs using LCs.