Extending the Broadening Limits in Silicon Waveguides by Pre-Shaping a Chirped Pump Pulse

Spectral broadening in silicon waveguides is usually inhibited at telecom wavelengths due to the two-photon and free-carrier absorption that typically depletes the pump before large broadening factors can be achieved. In this letter, we numerically demonstrate the greatly enhanced supercontinuum generation by adding a cubic spectral phase and an initial chirp to the input pulse. We show that the noise properties can also be significantly improved both in terms of signal-to-noise ratio and spectral coherence.