A Bragg grating fast tunable filter prototype working over a linear tuning range of 45 nm with a maximum tuning speed of 21 nm/ms has been realized. The tunable filter system is based on two piezoelectric stack actuators moving a mechanical device thus compressing an apodized fiber Bragg grating. The filter allows both traction and compression and can work in transmission and in reflection. It is designed to work with a channel spacing of 100 GHz according to the ITU specifications for wavelength division multiplexing systems.
Alessandro Iocco, Hans Georg Limberger, Rene Paul Salathe, Lorna A. Everall, Karen E. Chisholm, John A. R. Williams, and Ian Bennion, "Bragg Grating Fast Tunable Filter for Wavelength Division Multiplexing," J. Lightwave Technol. 17, 1217- (1999)