Agile and Broadband All-Optical Wavelength Conversion with Multi-Wavelength Lasers

We demonstrate a novel approach to all-optical wavelength conversion (AOWC) using a monolithically integrated InP multi-wavelength laser (MWL). By exploiting carrier-induced gain modulation and intermodal coupling within the common gain section, we achieve data wavelength conversion over a 1.3 THz range for signals up to 10 GBd, without the need for an external probe laser. The scheme relies on optical injection of the data signal into the MWL, where strong mode coupling enables transfer of the modulation to other longitudinal modes. A monolithically integrated feedback cavity provides agile switching between three longitudinal modes or even broadcasting across the three channels by adjusting the feedback phase. We evaluate the signal quality of the converted data through BER measurements for various symbol rates, showing both transparent conversion and, at low injection powers, even net signal gain. Complementary numerical simulations, based on a multimode extension of the Lang-Kobayashi rate equations, reveal the role of modal gain imbalance and cross-saturation in shaping the conversion efficiency. These results establish a scalable, compact, and energy-efficient route toward agile AOWC devices.