Lange, S.S.LangeWolf, N.N.WolfGruner, M.M.GrunerYan, L.L.YanKaiser, R.R.KaiserVelthaus, K.-O.K.-O.VelthausChoi, J.H.J.H.ChoiSchell, M.M.Schell2022-03-052022-03-052016https://publica.fraunhofer.de/handle/publica/24455310.1109/JLT.2015.2510228An optical transmitter incorporating a monolithically integrated laser and a traveling wave electrode in-phase and quadrature modulator is presented. A co-designed SiGe differential driver was co-packaged for highest quality push-pull modulation. With only 0.1-dB coupling loss between the laser and the modulator, and a low modulator switching voltage the transmitter power consumption was 1.1 W, which fits the CFP4 (analog coherent optics) ACO module overall budget of 6 W. Without DSP for precompensation, FEC or equalization, 32 GBd QPSK with 3 V-pp driving voltage and an error vector magnitude of <10% are presented. Operation with an optical signal-to-noise ratio larger than 14 dB is achieved before breaking the hard decision forward error correction threshold (3.8 x 10(-3)).en535journal article