Phase noise is one of the key limitations for phase-modulated signal in high-speed optical communication system as its information is coded in the optical phase.Therefore

phase noise monitoring technique is highly required in future reconfigurable and flexible optical communication system.It can provide real-time information about the quality of the transmitted signal during the fiber transmission.In this paper

we apply the phase sensitive characteristic in the parametric amplifying process and propose a phase noise monitoring method for Binary Phase Shift Keying（BPSK）signal based on dual-pump parametric amplifying in highly nonlinear fiber.The simulation results show that the phase noise monitoring can be successfully achieved in the range of 0 to 0.4 V

π

for 40Gbit/s BPSK signal.