Long period fiber gratings modulation by liquid crystal cladding

For future use in optical communications, external switches of the signal propagating in the fiber are needed. Up to now, only a few components have been developed which permit an external modulation of the signal. We propose here for the first time to our knowledge a modulation of the intensity based on the electrical reorientation of a nematic liquid crystal around a photoinduced long period grating operating at discrete wavelengths in the infrared range