Ultrafast nonlinear and strong-field phenomena in silicon-loaded nanoplasmonic waveguides

摘要

In this work, we summarize recent findings on ultrafast nonlinear and strong-field phenomena in silicon-loaded nanoplasmonic waveguides. Coupling ultrafast λ = 1.55μm pulses into such structures gives rise to both high-efficiency third harmonic generation (THG) and ponderomotive electron acceleration. We show THG efficiencies of 2.3 × 10~(-5) in waveguides with an ultracompact footprint of 0.43μm~2, resulting in visible green light emission. Remarkably, broadband white light emission is observed as well. This phenomenon is found to originate from an electron avalanche induced by the ponderomotive acceleration of electrons generated via two photon absorption. Thus, this nanoplasmonic device presents a versatile platform for realizing ultrafast nonlinear phenomenon within all-optical circuitry.