Novel ultrafast all-optical nonreturn-to-zero to return-to-zero format converter based on Sagnac interferometric structure

Abstract

Based on the Sagnac interferometric structure, a simple novel ultrafast scheme of an all-optical nonreturn-to-zero (NRZ) to return-to-zero (RZ) is proposed. The operations of this scheme at 40 Gbit/s 2 7 -1 PRBS sequences are simulated correctly with an output extinction ratio of more than 19.1 dB. Through a built theoretical model and numerical analysis, the operating characteristics of the scheme are illustrated. Furthermore, the carrier recovery time of the semiconductor optical amplifier (SOA) is no longer a crucial parameter to restrict the operation speed of this scheme. This scheme is potentially capable of all-optical NRZ-to-RZ format converter operation speeds to 80 Gbit/s thus far.