Fabrication of highly efficient grating band-pass filters and their applications in soliton propagation system

Abstract

We report here fabrication of highly efficient in-fiber grating bandpass filters using the established UV-side- exposure technique. Various combinations of passband/stopband and transmission/rejection of single- and multi-channel filters have been produced in hydrogenated standard telecom, high Ge-doped and B/Ge-codoped fibers. Up to > 60 dB rejection stopbands ranging from -2 nm to 55 nm, and passbands with 0.02 nm - 3 nm linewidths and transmissivity up to > 90% have been achieved with these devices. By concatenating several structures, a bandpass filter has been demonstrated with a combination of a 0.16 nm passband centered in a approximately 35 nm stopband, representing the highest reported finesse of 220 for any multi-nanometer stopband filter. We also report the first application of a grating bandpass filter for suppressing timing jitter in soliton propagation system, enabling transmission of 10 ps solitons over a distance of 2700 km.