Investigation of phase matching for third-harmonic generation in silicon slow light photonic crystal waveguides using Fourier optics.
Using 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.
Monat
Christelle
C
Institute of Photonics and Optical Science, Centre for Ultrahigh-bandwidth Devices for Optical Systems, School of Physics, The University of Sydney, NSW 2006, Australia. monat@physics.usyd.edu.au
Grillet
Christian
C
Corcoran
Bill
B
Moss
David J
DJ
Eggleton
Benjamin J
BJ
White
Thomas P
TP
Krauss
Thomas F
TF
D000465:Algorithms; D003460:Crystallization; D004867:Equipment Design; D005583:Fourier Analysis; D008027:Light; D008422:Materials Testing; D055095:Optics and Photonics; D017785:Photons; D012031:Refractometry / Q000379:methods; D012542:Scattering, Radiation; D012825:Silicon / Q000737:chemistry
D012825:Silicon