LAUSR

Sinc-shaped Nyquist pulses have wide applications in optical communications and microwave photonics. The quality of the generated Nyquist pulses has a significant effect on the overall performance of the communication system and the signal processing system. Generating high-quality Nyquist pulses with integrated silicon modulators is however still challenging due to the highly nonlinear response and fabrication-induced discrepancies of the device. We present a model for a silicon dual-parallel modulator with which the best possible quality of the generated optical frequency comb (OFC) and sinc-shaped Nyquist pulses can be obtained. In the model, the phase and amplitude deviations are taken into consideration. Device induced waveform and spectrum distortion can be well described. Based on the guidance of the model, a root-mean-square error of 2.8% is obtained between the experimentally generated signals and the ideal pulses, which proves the high accuracy of the model and its importance for high-quality Nyquist pulse generation.