Ultra-Wideband WDM Transmission Using PPLN-Based Optical Parametric Amplifier and Wavelength Converter

This paper reviews ultra-wideband inline-amplified WDM transmission systems, including bandwidth extension to the U-band, using optical parametric amplification and waveband conversion based on our high-efficiency periodically poled lithium niobate (PPLN) $\chi^{(2)}$-nonlinear waveguides.