Low-threshold supercontinuum generation in highly nonlinear chalcogenide nanowires

We demonstrate low-threshold supercontinuum generated in a highly nonlinear arsenic selenide chalcogenide nanowire with tailored dispersion. The tapered submicrometer chalcogenide fiber exhibits an ultrahigh nonlinearity, $n_2\sim 1.1\times {10}^{-17}{\mathrm{m}}^2∕\mathrm{W}$ and an effective mode area of $0.48\mathrm{\mu }{\mathrm{m}}^2$, yielding an effective nonlinearity of $\gamma \sim 93.4\mathrm{W}∕\mathrm{m}$, which is over 80,000 times larger than standard silica single-mode fiber at a wavelength of $\sim 1550\mathrm{nm}$. This high nonlinearity, in conjunction with the engineered anomalous dispersion, enables low-threshold soliton fission leading to large spectral broadening at a dramatically reduced peak power of several watts, corresponding to picojoule energy.