We propose a new optical serial-to-parallel converter using a phase-shifted preamble and Mach–Zehnder delay interferometers (MZDIs)
with high speed and low power consumption. From bit error rate (BER) analysis at 40 Gbit/s, operation with BER < 109 was obtained. We
also investigated the tolerance of the frequency mismatch of the MZDIs and the bit scalability. Tolerances of 8.1 and 1.0GHz for 1- and 8-
bit-delay MZDIs were obtained, respectively. We also obtained scalabilities of 27 and 15 bits for silica and InGaAsP-based material,
respectively.