Time and frequency domain measurements of solitons in subwavelength silicon waveguides using a cross-correlation technique

We report time domain measurements of the group-velocity-dispersion-induced and nonlinearity-induced chirping of femtosecond pulses in subwavelength silicon-on-insulator waveguides. We observe that at a critical input power level, these two effects compensate each other leading to soliton formation. Formation of the fundamental optical soliton is observed at a peak power of a few Watts inside the waveguide. Interferometric cross-correlation traces reveal compression of the soliton pulses, while spectral measurements show pronounced dispersive (Cherenkov) waves emitted by solitons into the wavelength range of normal group velocity dispersion.