All-optical NRZ-to-RZ reconversion from the red-chirped NRZ signal generated by the RZ-to-NRZ converter using an SOA-loop-mirror

This paper aims to demonstrate experimentally a new all-optical non-return-to-zero (NRZ) to return-to-zero (RZ) data format reconversion from the red-chirped NRZ signal, generated by the RZ-to-NRZ converter, using a semiconductor optical amplifier in a fiber loop mirror (so-called an SOA-loop-mirror). The primary merit of the proposed NRZ-to-RZ reconversion is that no additional optical clock is required in the process, unlike other conventional methods. While the optical power penalty for the RZ-to-NRZ conversion using an SOA-loop-mirror was 1.64 dB, the proposed NRZ-to-RZ reconversion penalty was 0.6 dB compared to that of the original input RZ signal.