An octave spanning mid-infrared frequency comb generated in a silicon   nanophotonic wire waveguide
  We demonstrate an octave-spanning frequency comb with a spectrum covering wavelengths from 1,540 nm up to 3,200 nm. The supercontinuum is generated by pumping a 1-cm long dispersion engineered silicon wire waveguide by 70 fs pulses with an energy of merely 15 pJ. We confirm the phase coherence of the output spectrum by beating the supercontinuum with narrow bandwidth CW lasers. We show that the experimental results are in agreement with numerical simulations. 
Bart Kuyken, Takuro Ideguchi, Simon Holzner, Ming Yan, Theodor W.   Haensch, Joris Van Campenhout, Peter Verheyen, St\'ephan...
physics.optics