Spatiotemporal nonlinear optics in arrays of subwavelength waveguides

Here we study theoretically and experimentally spectral broadening and excitation of solitonic supermodes in an array of three coupled silicon wires. Each wire is 220 nm thick, 380 nm wide and 3 mm long. The array is located on the silica glass substrate and surrounded by air. The wall-to-wall separation between the wires is 600 nm. For the chosen dimensions, the zero GVD wavelength of the quasi-TE mode of single wire is located at 1.62 μm. For pulses with the duration of-100 fs, the dispersion and coupling lengths are matched around the pump wavelength of 1.5μm and are of the order of 1 mm.