PPLN-waveguide based tunable wavelength conversion of QAM data within the C-band

Tunable optical wavelength conversion of a 40 Gb/s 16-ary quadrature amplitude modulated signal within the C-band is demonstrated by cascaded sum frequency generation and difference frequency generation in a periodically-poled lithium niobate module. System experiments with conversion efficiencies of ~ 7.5 dB (excluding module loss) are presented. Bit-error ratio measurements confirm excellent conversion performance.