Characterisation of novel polarisation-insensitive configurations of fibre optical parametric amplifiers

We experimentally compare two novel polarisation-insensitive fibre optical parametric amplifiers configurations by amplifying 35GBaud PDM-QPSK signal in WDM environment and measuring BER. We demonstrate that one configuration provides 1dB better Q ² in linear regime, while another improves Q ² by up to 4dB in nonlinear regime.