Giant anomalous self-steepening and temporal soliton compression in silicon photonic crystal waveguides

Self-steepening (SS) is enhanced by slow-light effects in photonic crystal waveguides (PhCWs), with coefficients as large as hundreds of femtoseconds, and it plays an important role in temporally compressed solitons with narrow widths. Here, we investigate the soliton evolution in silicon PhCWs through experiments and numerical simulations; the simulated results agree well with the experimental measurements and help in revealing the physical mechanism of high-order soliton evolution. The dual opposite effects of giant anomalous SS on temporal soliton compression are demonstrated for the first time, i.e., the SS weakens or improves the compression competing with the effects of third-order dispersion (TOD) through two different physical mechanisms. It is also found that SS flattens or steepens the pulse leading edge depending on the strength of the positive TOD perturbation. These results promote the understanding of high-order solitons and can help with the design of suitable dispersion engineered silicon waveguides for superior on-chip temporal pulse compression for optical interconnects, data processing, and microwave photonics.