Monat, ChristelleGrillet, ChristianCorcoran, BillMoss, David J.Eggleton, Benjamin J.White, ThomasKrauss, Thomas F.2016-05-162016-05-161094-4087http://hdl.handle.net/1885/101245Using Fourier optics, we retrieve the wavevector dependence of the third-harmonic (green) light generated in a slow light silicon photonic crystal waveguide. We show that quasi-phase matching between the third-harmonic signal and the fundamental mode is provided in this geometry by coupling to the continuum of radiation modes above the light line. This process sustains third-harmonic generation with a relatively high efficiency and a substantial bandwidth limited only by the slow light window of the fundamental mode. The results give us insights into the physics of this nonlinear process in the presence of strong absorption and dispersion at visible wavelengths where bandstructure calculations are problematic. Since the characteristics (e.g. angular pattern) of the third-harmonic light primarily depend on the fundamental mode dispersion, they could be readily engineered.The support of the Australian Research Council through its Centre of Excellence and Discovery Grant programs is gratefully acknowledged. Additional acknowledgment is given to the support of the Department of Education, Science and Technology through the International Science Linkages program. The silicon samples were fabricated in the framework of the EU-FP6 funded ePIXnet Nanostructuring Platform for Photonic Integration (www.nanophotonics.eu).© 2010 Optical Society of Americahttps://creativecommons.org/licenses/by/4.0/algorithmscrystallizationequipment designfourier analysislightmaterials testingphotonsrefractometryscattering, radiationsiliconoptics and photonics2010-03-2910.1364/OE.18.0068312016-06-14CC BY 4.0