Raman-assisted phase sensitive amplifier using a fiber Bragg grating-based tunable phase shifter.

A low-loss Raman-assisted phase sensitive amplifier (PSA) with a similar to 20 dB signal net gain is experimentally demonstrated. The amplitude and phase adjustment for PSA are achieved by using non-uniform Raman gain and a tunable fiber Bragg grating (FBG), respectively. The total component loss of the system is measured to be similar to 8 dB. By tuning the FBG central wavelength, (1) an up to 5.6 dB signal gain improvement is obtained; and (2) a similar to 4dB receiver sensitivity enhancement is observed for 20 and 25 Gbaud quadrature phase shift keying signals and a 10 Gbaud 16-quadrature amplitude modulation signal. (C) 2018 Optical Society of America