This paper uses an in-band optical performance monitoring (OPM) method based on autocorrelation, offering high sensitivity and multi-damage monitoring. The proposed method effectively detects both optical signal-to-noise ratio (OSNR) and chromatic dispersion (CD) across a broad range of cumulative dispersion values. Utilizing the Wiener– Khintchine theorem, we retrieve the autocorrelation of signals through spectrum retrieval without the need for phase-matched second-harmonic generation. Dispersion is determined through variations in the autocorrelation function curve after cross-phase modulation (XPM), while OSNR is determined based on the normalized autocorrelation function and the characteristics of noisy signals. Simulation results demonstrate the robustness of this method across various modulation formats and input optical power levels. For 32 Gbaud signals, the OSNR monitoring error remains below 0.5 dB, with an effective monitoring range extending up to 30 dB. Additionally, the dispersion monitoring range reaches 800 ps/nm, confirming the broad applicability of this approach for high-capacity optical systems.
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