Octave-spanning coherent supercontinuum generation in a silicon nitride waveguide.

ABSTRACT

We demonstrate the generation of a supercontinuum spanning more than 1.4 octaves in a silicon nitride waveguide using sub-100-fs pulses at 1 µm generated by either a 53-MHz, diode-pumped ytterbium (Yb) fiber laser or a 1-GHz, YbCaAlGdO(4) (YbCALGO) laser. Our numerical simulations show that the broadband supercontinuum is fully coherent, and a spectral interference measurement is used to verify that the supercontinuum generated with the YbCALGO laser possesses a high degree of coherence over the majority of its spectral bandwidth. This coherent spectrum may be utilized for optical coherence tomography, spectroscopy, and frequency metrology.