Wavelength Converter for Polarization-Multiplexed 100-G Transmission With Multilevel Modulation Using a Bismuth Oxide-Based Nonlinear Fiber

We demonstrate a four-wave-mixing-based wavelength converter suitable for coherent optical transmission at 100 Gb/s/λ and beyond that uses phase-diversity and nonconstant amplitude modulation formats. Our setup consists of 2 m of bismuth oxide-based nonlinear fiber and two copolarized external cavity pump lasers. We demonstrate wavelength conversion of 112-Gb/s polarization-multiplexed return-to-zero quadrature phase-shift keying and 144-Gb/s 16-ary quadrature-amplitude modulation signals. Less than 0.4-dB optical signal-to-noise ratio penalty at BER = 2 × 10^-3 due to wavelength conversion was measured.