Single device for excitation of both flexural and longitudinal acousto-optic effects in fiber Bragg gratings

Experimental results on the acoustic modulation of fiber Bragg gratings are presented. Two main effects are achieved for the acousto-optic effect, one due to the longitudinal vibration mode of the fiber and the other due to the flexural mode. Using the flexural effect, the FBG reflectivity can be attenuated up to 26 dB, with a switching time of 63 ¿s. Using the longitudinal effect, lateral lobules separated by 0.3 nm can be induced.