Studies of long-period fiber grating devices coated with the liquid crystal layer tuned near the phase-matching turning point

In this work a unique structure is studied, namely the liquid crystal long-period fiber grating (LC-LPFG). The LPFG provide a mechanism for producing a wavelength-dependent attenuation in the transmission spectrum, which can be controlled, e.g. by surrounding refractive index [1-2]. In this context, the use of LC materials has gained a particular attention since their exceptional properties (like thermo-optic effects associated with their birefringence, dielectric anisotropy and the thermal dependence of their refractive indices [3]) can offer a new platform for tunable fiber devices.