Mechanical Tuning of a Fiber Bragg Grating for Optical Networking Applications

We investigate the sensitivity of fiber Bragg gratings, FBGs, to a longitudinal mechanical stress. Tuning ranges of up to 10 nm have been obtained in a prototype based on axial stretching/compression mechanism achieved by actuating on a micrometer screw that pulls/pushes the fiber. Preliminary results indicate a great potential to telecommunication applications, despite a slight sliding of the tuning screw, which has lead to an average spectral shift of 0.3 nm. In fact, the long term stability of a reconfigurable Optical Drop Multiplexer, ODM, employing the tunable FBG filter, has been evaluated in a 10 nm band showing a flat Bit Error Ratio, BER, performance after a initial period of nearly 15 minutes. The same tuning positions have been tested in a error free 10 Gb/s transmission along 25 km of either dispersion shifted, DS, and non-zero dispersion shifted, NZD, fibers, showing negligible power and BER variation.