Polarization- insensitive fibre optic parametric amplifier with gain bandwidth of 35 nm in L-band

We experimentally demonstrate a polarisation-insensitive fibre optic parametric amplifier (PI-FOPA) with the record wide gain bandwidth of 35 nm. We employ the PI-FOPA to amplify the full C- band equivalent 42x100GHz-spaced channels with net gain >10 dB and polarisation-dependent gain <0.5 dB in the wavelength range between 1580 nm and 1615 nm.