Parametric amplification of a 640 Gbit/s RZ-DPSK signal. - Zohreh Lali-Dastjerdi; Michael Galili; Hans Christian Hansen Mulvad; Hao Hu 009; Leif Katsuo Oxenløwe; Karsten Rottwitt; Christophe Peucheret (OFC/NFOEC, 2013)