High Baud Rate All-Silicon Photonics Carrier Depletion Modulators

We achieved high performance high speed silicon photonics carrier-depletion Mach-Zehnder modulation with commercial foundry by co-optimization of doping and device design assisted with an accurate electro-optical (EO) model. We demonstrated high performance IQ modulators operating at 85 Gbaud 16 QAM and 64 Gbaud 64 QAM with extinction ratio of over 25 dB. For the design of the high performance all-silicon carrier depletion modulator, we developed modeling and design tools to provide not only accuracy, but also efficiency in the simulation of distributed optical and electronic characteristics of travelling waveguides with different designs of optical and microwave waveguides under various doping conditions, which allow the co-design of velocity phase match between optical and microwave waveguides and the impedance match between microwave travelling waveguide and terminal impedance. Our experimental characterization test data agreed well with the model simulation data. More recently, with practical Nyquist filter and linear compensation in commercial arbitrary wave generator (AWG) and optical modulation analyzer (OMA), we demonstrated 100 Gbaud 32 QAM with an all-silicon IQ modulator, which has 6 dB electro-optical bandwidth of 50 GHz and BER achieving FEC threshold with a modern FEC, showing the potential for Tb/s applications.