Liquid crystal long-period fiber grating as a sensing element for electric field and temperature measurements

The main goal of the presented work is to integrate a long-period fiber grating (LPFG) and liquid crystal (LC) material into a hybrid structure, called an LC-LPFG, in order to develop innovative devices for sensing physical quantities. For this purpose we used specially designed low-birefringence LC mixtures whose ordinary refractive index is lower than that of silica in a certain range of temperatures. This combination allowed us to dynamically change the propagation properties of the cladding modes in the LC-LPFGs by varying the temperature and the electric field. This design of LC-LPFGs exhibits extraordinary sensing properties.