All-optical header erasure and penalty-free rewriting in a fiber-based high-speed wavelength converter

All-optical erasure and rewriting of 2.5-Gb/s nonreturn-to-zero (NRZ) data from high-speed return-to-zero (RZ) data has been demonstrated using a fiber-based wavelength converter. Such a wavelength converter will block the low frequencies of the NRZ data while converting the RZ pulses. This approach uses the frequency discriminating feature of the wavelength converter, and does not require active control. Penalty-free rewriting of new NRZ data was then performed.