Demonstration of an Ultra-Flat Raman-Enhanced Fibre Optical Parametric Amplifier (FOPA) with >110nm Gain-Bandwidth

We experimentally demonstrate a Raman-enhanced FOPA achieving record unfiltered gain variation of only +-0.5dB over 111nm bandwidth and with 9.6dB gain. We amplify a 60Gb/s QPSK signal error-free across the L-band with maximum Q2 penalty of 0.9+-0.3dB.