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arXiv · 1707.07646

Nonlinear carrier dynamics in silicon nano-waveguides

Ivan Aldaya·Andres Gil-Molina·Julian L. Pita·Lucas H. Gabrielli·Hugo L. Fragnito·Paulo Dainese
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Abstract

Carrier recombination dynamics in strip silicon nano-waveguides is analyzed through time-resolved pump-and-probe experiments, revealing a complex recombination dynamics at densities ranging from ${10^{14}}$ to ${10^{17}}\,$cm$^{{-3}}$. Our results show that the carrier lifetime varies as recombination evolves, with faster decay rates at the initial stages (with lifetime of ${\sim 800}\,$ps), and much slower lifetimes at later stages (up to ${\sim 300}\,$ns). We also observe experimentally the effect of trapping, manifesting as a decay curve highly dependent on the initial carrier density. We further demonstrate that operating at high carrier density can lead to faster recombination rates. Finally, we present a theoretical discussion based on trap-assisted recombination statistics applied to nano-waveguides. Our results can impact the dynamics of several nonlinear nanophotonic devices in which free-carriers play a critical role, and open further opportunities to enhance the performance of all-optical silicon-based devices based on carrier recombination engineering.

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Ivan Aldaya, Andres Gil-Molina, Julian L. Pita, Lucas H. Gabrielli, Hugo L. Fragnito, Paulo Dainese. 2017-07-24. Nonlinear carrier dynamics in silicon nano-waveguides. https://arxiv.org/abs/1707.07646

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