InP DHBT Very High Speed Power-DACs for Spectrally Efficient Optical Transmission Systems

This paper reports on very high speed large swing digital-to-analog converter (DAC) suiting the generation of spectrally efficient optical transmission signals. 2-bit and 3-bit DACS with up to 4 Vpp swing, operating up to 50 GBaud, have been fabricated using our InP DHBT technology (F
_T
~280 GHz, F
_MAX
~270 GHz, BV
_CE0
~5 V). These chips have been packaged and used to generate 16- and 64-QAM signals in optical transmission experiments at various bitrates.