Impact of Dispersion Effects on Temporal-Convolution-Based Real-Time Fourier Transformation Systems

The impact of dispersion effects on temporal-convolution-based real-time Fourier transformation (RTFT) systems, including the residual 2
^nd
-order dispersion effect, the 3
^rd
-order dispersion effect, and their joint effect, is theoretically analyzed. To reduce these effects, an optical RTFT system based on a bidirectional chirped fiber Bragg grating (CFBG) and an optical filter is proposed. Only one optical pulse source, a bidirectional CFBG, a Mach–Zehnder modulator (MZM) and a photodetector (PD) are needed. RTFT with a bandwidth of 40 GHz and a frequency resolution of 0.7 GHz has been experimentally achieved.