Performance Comparison of Gated and Nongated All-Optical Thresholding Detection Schemes Using Mach–Zehnder Interferometers in SPECTS O-CDMA

This letter discusses the all-optical thresholding functionality of a differential-mode Mach-Zehnder interferometer for optical code-division multiple-access under two different configurations and compares their performances. Simulation results indicate that the gated operation outperforms the nongated operation. The gated operation allows efficient recovery of the correctly decoded signal in the presence of an interferer at 10 Gb/s, with a required pulse energy of only 200 f J.