Software-defined optical transmission

Progress in electronic data processing enables software-defined optical (SDO) transmission. Modulation formats and symbol rates are set by software-controlled field programmable gate arrays (FPGA). We demonstrate a real-time SDO transmitter for 8 modulation formats, which can be swapped in 5 ns. Single-polarization 64QAM symbol generation at 28 GBd allows transmitting 168 Gbit/s real-time data. We further present a 101.5 Gbit/s single-polarization OFDM transmitter based on real-time FPGA processing, where we modulate 58 subcarriers with 16QAM data. For terabit OFDM reception, optical pre-processing is required to demultiplex high-bitrate signals down to lower-bitrate tributaries, which then can be processed digitally. We discuss a 10.8 Tbit/s receiver employing an all-optical fast Fourier transform to demultiplex 75 optical subcarriers modulated with 16QAM-formated symbols at a rate of 16 GBd.