High-conversion-efficiency all-optical wavelength converter based on cascaded highly nonlinear fibers

All-optical wavelength converters based on parametric processing of highly nonlinear fiber (HNLF) can provide low energy consumption, fast process speed, and modulation format agnosticism. A longer HNLF with a larger nonlinear coefficient and high pump power will contribute to achieve higher conversion efficiency. However, the injected pump power to the fiber is limited by its stimulated Brillouin scattering threshold, where longer fibers always have lower threshold powers. In the paper, we propose an all-optical wavelength converter with higher conversion efficiency by cascading two different HNLFs. We experimentally achieved -8  dB conversion efficiency and good converted signals with negligible power penalties.