Bit-rate-transparent optical return-to-zero-to-nonreturn-to-zero format conversion based on linear spectral phase filtering of the RZ signal

We propose a novel and simple design for all-optical bit-rate-transparent return-to-zero (RZ)-to-nonreturn-to-zero (NRZ) telecommunication data format conversion based on linear spectral phase filtering of the RZ signal. The proposed concept is numerically analyzed and experimentally validated through successful format conversion of a 640 Gbit/s coherent RZ signal into the equivalent NRZ time-domain data using a simple phase filter realized by a commercial optical waveshaper.