100 Gbaud quadrature-amplitude modulation (QAM) signaling with silicon photonic electro-absorption modulators

We demonstrate up to 100 Gbaud quadrature- amplitude modulated(QAM) signal generation with monolithic silicon I/Q-modulator based on silicon-germanium (SiGe) electro-absorption modulators (EAM). Single-polarization quadrature phase-shift keying(SD-QPSK) signaling at symbol rates of 100Gbaud with BERs below the soft-decision forward error correction(FEC) limit is shown. SD-QPSK optical signal generation and transmission over 80km single-mode fiber(SMF) are demonstrated at symbol rates of 50 Gbaud with BER of less than 1e-5. The effect of the frequency roll-off used for Nyquist pulse shaping with raised cosine frequency response is studied for SD-QPSK 50Gbaud signals. Furthermore, 16QAM signals at symbol rates of 50Gbaud are generated in a differentially driven configuration similar to the conventional Mach-Zehnder modulator(MSM) based in-phase quadrature(I/Q) modulators.