Research On Multi-Wavelength Phase Synchronization Technology Of MPSK Signal

All-optical signal processing technology has ultra-fast response time and does not require optical-to-electrical-to-optical conversion.Applying it to optical network switching nodes can significantly improve resource scheduling efficiency and build an elastic all-optical network with flexible spectrum resources.The current all-optical network is mainly based on wavelength division multiplexing technology.The complex nonlinear effect between channels and the random carrier phase greatly hinders the development of multi-wavelength signal processing technology.Therefore,effectively alleviating the inter-channel crosstalk is significant for multiwavelength signal processing.In addition,for high-order modulation formats such as MPSK,a stable phase relationship is conducive to the aggregation and de-aggregation of multi-wavelength signals,thereby improving the compatibility between different types of networks and realizing flexible scheduling and efficient grooming of service flows.Focusing on the all-optical processing technology of multi-wavelength signals,a phase synchronization method for multi-wavelength MPSK signals is proposed in this paper,and multi-wavelength signal aggregation and de-aggregation systems are designed on this basis.The main research work is summarized as follows:1.A phase synchronization method is proposed to solve the problem of random carrier phases between multi-wavelength MPSK signals.The nonlinear effect and time-lens are used to reload the random initial phases of the input signals into a synchronized phase,thereby reducing the difficulty of subsequent processing.This method is valid for all MPSK formats and can avoid the problem of nonlinear crosstalk between different wavelengths.The phase synchronization system of the multi-wavelength QPSK signal is simulated and realized.The feasibility of the scheme is verified by the time-frequency domain waveform and the input and output constellation diagram.The system performance is evaluated by analyzing the bit error rate and error vector magnitude under different optical signalto-noise ratios.2.Aiming at the problem of flexible scheduling of business flows in the optical network,based on the phase synchronization method of multiwavelength MPSK signals,the aggregation and de-aggregation schemes of multi-wavelength vector optical signals are respectively proposed.In the aggregation scheme,the principle of vector superposition and wavelength conversion is used to aggregate the MPSK signal into a higher-order modulation format,which has wavelength transparency;in the deaggregation scheme,based on the time-lens and phase sensitive amplification technology,only one pair of pumps is needed to de-aggregate the multi-wavelength MPSK signal into a low-order modulation format.Likewise,to evaluate the system’s performance,both the time-frequency domain waveforms,constellation diagrams,bit error rate,and error vector magnitude curves are analyzed.