Design of Optical Transmission Link with Cascaded Fibre-Optical Parametric Amplifiers

We present the design of an optical transmission link with cascaded in-line fibre-optical parametric amplifiers (FOPAs), which operate with a multi-tone modulation of the pump phase to support the required signal gain. A novel, online digital signal processing algorithm is included in the receiver to mitigate the accumulated phase and amplitude signal distortions that are induced by the pump modulation at each FOPA stage. We numerically demonstrate that our proposed design achieves substantial
$Q^{2}$
-factor performance benefits in 16 quadrature-amplitude modulation signal transmission over long distances.