Transmission of 160.7-GBaud 1.64-Tbps Signal Using Phase-Interleaving Optical Modulator and Digital Spectral Weaver

We demonstrate a new optical-domain bandwidth extension technology with a simple optical configuration. We use an integrated optical phase-interleaving in-phase-and-quadrature modulator (PI-IQM) consisting of a differential phase modulator followed by a pair of IQMs in combination with an 8-by-4 digital spectral weaver (DSW). With them, we can synthesize arbitrary optical signals with bandwidths up to twice the analog bandwidth of digital-to-analog converters (DACs). The optical configuration is simpler than those of conventional frequency- or time-interleaving approaches. We fabricated the PI-IQM using an InP n-p-i-n platform and tested it with driving signals with a bandwidth of 41 GHz generated by the DSW and 93.7-GS/s DACs. As a result, we successfully generated 160.7-GBaud probabilistically shaped quadrature amplitude modulation signals and achieved net data rates of 1.68 Tbps at back to back and 1.64 Tbps after 80-km transmission.