Photocurrent-assisted wavelength (PAW) conversion with electrical monitoring capability using a traveling-wave electroabsorption modulator

A new mechanism of cross-absorption modulation is proposed and experimentally demonstrated to assist wavelength conversion using a traveling-wave electroabsorption modulator (TW-EAM). The photocurrent signal generated by the pump propagates along the TW electrodes and changes the absorption of the waveguide, which imprints data to the probe. The photocurrent signal can also be received by an external electronic circuit to provide monitoring capability. This photocurrent-assisted mechanism does not rely on the saturation of absorption and has the potential to reduce the high pumping power required by EAM-based wavelength converters. Using 2.5-Gb/s nonreturn-to-zero data, the conversion range can cover 30 nm in C-band and the lowest power penalty is 0.5 dB.