Efficient complementary metal-oxide semiconductor-based nonlinear optical devices in the near-infrared are in strong demand.Due to two-photon absorption in silicon,however,much nonlinear research is shifting towards unconventional photonics platforms.In this work,we demonstrate the generation of an octave-spanning coherent supercontinuum in a silicon waveguide covering the spectral region from the near-to shortwave-infrared.With input pulses of 18 pJ in energy,the generated signal spans the wavelength range from the edge of the silicon transmission window,approximately 1.06 to beyond 2.4 μm,with a -20 dB bandwidth covering 1.124-2.4 μm.An octave-spanning supercontinuum was also observed at the energy levels as low as 4 pJ (-35 dB bandwidth).We also measured the coherence over an octave,obtaining g(1)12(λ) ＞90％,in good agreement with the simulations.In addition,we demonstrate optimization of the third-order dispersion of the waveguide to strengthen the dispersive wave and discuss the advantage of having a soliton at the long wavelength edge of an octave-spanning signal for nonlinear applications.This research paves the way for applications,such as chip-scale precision spectroscopy,optical coherence tomography,optical frequency metrology,frequency synthesis and wide-band wavelength division multiplexing in the telecom window.