%0 Journal Article %@ 0146-9592 %A Lavdas, S %A Zhao, S %A Panoiu, NC %A Driscoll, JB %A Grote, RR %A Osgood, RM %D 2014 %F discovery:1443006 %J Optics Letters %K Wavelength conversion devices; Nonlinear optical devices; Waveguides, channeled; Nonlinear optics, four-wave mixing; (190.4975) Parametric processes; Nonlinear optics, integrated optics. %N 13 %P 4017 - 4020 %T Wavelength conversion and parametric amplification of optical pulses via quasi-phase-matched four-wave mixing in long-period Bragg silicon waveguides %U https://discovery.ucl.ac.uk/id/eprint/1443006/ %V 39 %X We present a theoretical analysis supported by comprehensive numerical simulations of quasi-phase-matched fourwave mixing (FWM) of ultrashort optical pulses that propagate in weakly width-modulated silicon photonic nanowire gratings. Our study reveals that, by properly designing the optical waveguide such that the interacting pulses copropagate with the same group velocity, a conversion efficiency enhancement of more than 15 dB, as compared to a uniform waveguide, can readily be achieved. We also analyze the dependence of the conversion efficiency and FWM gain on the pulse width, time delay, walk-off parameter, and grating modulation depth. © 2014 Optical Society of America. %Z This version is the author-accepted manuscript. For information on re-use, please refer to the publisher’s terms and conditions.