Technique for suppression of pattern dependence in a semiconductor-optical-amplifier wavelength converter

Wavelength converters that employ cross-gain modulation (XGM) in semiconductor optical amplifiers (SOAs) are limited in bit rate by the amplifier's pattern dependent response. We substantially suppress this pattern dependence by converting the phase modulation at the data transitions to amplitude modulation using a fiber grating filter. We use this technique to obtain error-free wavelength conversion of 10-Gb/s nonreturn-to-zero (NRZ) data using an SOA that showed an error floor at 10/sup -5/ bit-error rate (BER) when used alone.