Ultra-Narrow Pulse Shaping Based on Integrated Chirped Grating-Assisted Contradirectional Couplers

The on-chip pulse shaper is a key device that enables ultra-high-speed, ultra-wideband linear signal processing in a compact size with low power consumption. We propose a pulsed time-domain waveform shaping method based on chirped period Bragg gratings and contradirectional couplers, allowing flexible control of the grating’s period to achieve frequency-specific reflections and reflection strengths. We demonstrate two types of time-domain sawtooth waveform generation and analyze the relationship between the time-domain waveforms and the linear chirp period. Compared to other waveform generation schemes based on Fourier synthesis or time-domain synthesis, our method achieves direct time-domain pulse shaping through grating period design. The proposed method achieves sawtooth pulse generation with a pulse width of 6.1 ps.