180-GBaud Nyquist Shaped Optical QPSK Generation Based on a 240-GSa/s 100-GHz Analog Bandwidth DAC

We demonstrate the generation and coherent detection of 180-Gbaud QPSK using a 240-GSa/s, 100-GHz bandwidth digital-to-analog converter (DAC). We achieve a 6.5-dB implementation penalty for the 360-Gb/s line rate single-carrier and single-polarization system.