Wavelength conversion and parametric amplification of optical pulses via quasi-phase-matched FWM in long-period Bragg silicon waveguides

TL;DR

This paper theoretically analyzes quasi-phase-matched four-wave mixing in silicon nanowire gratings, demonstrating over 15 dB conversion efficiency enhancement for ultrashort pulses through proper waveguide design and comprehensive numerical simulations.

Contribution

It introduces a novel design approach for silicon waveguides that significantly enhances FWM efficiency by matching group velocities, supported by detailed numerical analysis.

Findings

Over 15 dB conversion efficiency enhancement achieved.

Efficiency depends on pulse width, delay, walk-off, and grating depth.

Proper waveguide design enables efficient wavelength conversion.

Abstract

We present a theoretical analysis supported by comprehensive numerical simulations of quasi phase-matched four-wave 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 co-propagate 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.