Acousto-Optic Notch Filter Dynamically Induced in a Chirped Fiber Bragg Grating

A notch filter acoustically induced in a 1-cm-long chirped fiber Bragg grating is experimentally investigated. The notch reflectivity (-5.8 to -32 dB) and the bandwidth (2.2 to 1.3 nm) are tuned by an electrical signal. The reduction of the modulator size and the grating length, compared with previous works with acousto-optic modulation, points to more efficient acousto-optic devices in standard single-mode optical fibers.