Photonic Label Recognition by Time-Space Conversion and 2-D Spatial Filtering With Delay Compensation

An optical-label recognition system using time-to-space conversion, spatial Vander-Lugt 2-D correlation, and postprocessing with a slit and a delay compensator is proposed. The postprocessing, with the narrow slit and a prism for the time-delay compensation, makes it possible to distinguish the labels, consisting of a time series of optical pulses. For 4-b binary phase-shift-keying labels at 160 Gb/s, eight different labels are proved to be distinguished by the computer simulation. The contrast ratio of autocorrelation to cross-correlation is 1.61 and 2.5 without and with time gating, respectively.