All-optical clock recovery for both RZ and NRZ data

An all-optical clock recovery scheme for both the nonreturn-to-zero and the return-to-zero formats has been proposed and successfully demonstrated. Clock extraction, enhancement, and clock-to-data suppression were realized by a semiconductor optical amplifier and a fiber Bragg grating. Clock recovery was achieved using a two-section gain-coupled distributed-feedback laser. The scheme has large dynamic range of input power for both formats.