All-optical 42.6 Gbit/s NRZ to RZ format conversion by cross-phase modulation in single SOA

Abstract

A 42.6 Gbit/s all-optical non-return-to-zero (NRZ) to return-to-zero (RZ) format converter using a single SOA followed by an asymmetrical Mach-Zehnder interferometer is presented. The format converter generates a correctly-coded RZ signal with a controllable duty-cycle. It has the advantages of flexible input NRZ wavelength, preserved input polarity, negative bit error rate power penalty and low switching pulse energy (15fJ).