Design and Operation of a Monolithically Integrated Two-Stage Tunable All-Optical Wavelength Converter

We report on the design and testing of a novel two-stage wavelength-converter architecture, monolithically fabricated in indium phosphide. Two widely tunable integrated sampled-grating distributed Bragg reflector lasers are utilized on chip as probes in both converter stages. The architecture provides a first-stage tunable signal that is internal to the chip ( $\lambda_{\rm internal}$), facilitating cascaded integration of wavelength-sensitive structures, or allowing wavelength conversion for cases where the input wavelength is equal to the output wavelength ($\lambda_{\rm input} = \lambda_{\rm output}$ ). Output wavelength tuning over 35 nm is shown, and error-free wavelength conversion for $\lambda_{\rm input} = \lambda_{\rm output}$ is demonstrated for four wavelengths over a 20-nm range at 2.5 Gb/s. Dynamic range measurements show less than 2 dB of power penalty over a 15-dB variation in input power.