Ultrafast optical distortion equalizer using time-frequency domain processing

An ultrafast optical distortion equalizer using time-frequency domain processing that allowed bitwise adaptive compensation of ad hoc optical distortions is described. In the time-frequency domain, because all distortions are distilled to variations in the arrival times of each multiplexed spectral component, they can be treated as one time-frequency distribution. Spatial channels are used to separate spectral components in a distorted bit pulse into plural channels for time-frequency demultiplexing (TF-DEMUX). After TF-DEMUX, temporal and spectral adjustments are achieved through a hard-wired optical delay line for each spatial channel so that each fixed time difference can be canceled. The operation of the proposed ultrafast optical distortion equalizer for uncharacterized optical distortion of chromatic dispersion and timing jitter ranging from several picoseconds to subpicoseconds was demonstrated.