2-Dimensional Spatio-Temporal Signal Processing for Dispersion Compensation in Optical Systems

An inherent limitation of dispersive optical systems is the frequency-selective response of the optical systems. This paper presents a solution based on spatio-temporal digital processing that exploits the optical phase diversity to create a flat frequency response in optical systems. The digital signal processing algorithm creates a flat frequency response even when the system´s transfer function includes deep nulls in the frequency response. The proposed scheme can be applied to both baseband and passband systems as well any optical signal processing system that suffers from dispersion. As an example, we present a two-branch optical system with two MZ modulators. We show that while the flat bandwidth of the original system is very limited, the proposed solution increases the overall achievable SNR to 52 dB at frequencies up to 20 GHz.