All-optical passive clock extraction of 40 Gbit/s NRZ data using narrow-band filtering

A passive all-optical scheme for clock extraction from non return-to- zero (NRZ) data has been proposed based on narrow-band filtering. Two equally effective embodiments of the proposed scheme have been demonstrated experimentally. A carrier-to-noise ratio (CNR) of 30 dB has been achieved at 40 Gbit/s using fiber Bragg gratings (FBG).