High symbol rate 200-GBd PDM-QPSK transmission over 3520 km using ultra-broadband InP-DHBT analogue multiplexer

Long-haul transmission over 3520 km in a 4.725-THz WDM configuration with 225-GHzspacing in the C-band has been successfully demonstrated with a high-symbol-rate 200-GBd polarization-division-multiplexed QPSK signal, which was generated using in-house >110-GHz analogue multiplexers and >130-GHz-bandwidth electrical amplifiers based on ultra-broadband indium phosphide technologies.