Silicon dual-series Mach–Zehnder modulator with high linearity

In this Letter, we demonstrate a highly linear silicon modulator based on the dual-series Mach-Zehnder modulator (MZM) architecture. The two sub-MZMs are biased at quadrature points of opposite polarities. A proper power-splitting ratio of the driving RF signal on the two sub-MZMs enables the suppression of the third order intermodulation distortion (IMD3). The spurious-free dynamic ranges (SFDRs) for IMD3 are 109.5/100.5 dB·Hz^2/3 at 1/10 GHz. In contrast, the reference single MZM on the same chip exhibits SFDRs of 95.2/86.8 dB·Hz^2/3 at 1/10 GHz at its optimal reverse bias voltage.