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arXiv · 2411.02315

Few photons probe third-order nonlinear properties of nanomaterials in a plasmonic nanocavity

Anupa Kumari·MohammadReza Aghdaee·Mathis Van de Voorde·Oluwafemi S. Ojambati
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Abstract

Quantification of nonlinear optical properties is required for nano-optical devices, but they are challenging to measure on a nanomaterial. Here, we harness enhanced optical fields inside a plasmonic nanocavity to mediate efficient nonlinear interactions with the nanomaterials. We performed reflection Z-scan technique at intensity levels of kWcm^2, reaching down to two photons per pulse, in contrast to GWcm^2 in conventional methods. The few photons are sufficient to extract the nonlinear refractive index and nonlinear absorption coefficient of different nanomaterials, including perovskite and Au nano-objects and a molecular monolayer. This work is of great interest for investigating nonlinear optical interactions on the nanoscale and characterizing nanomaterials, including fragile biomolecules.

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Anupa Kumari, MohammadReza Aghdaee, Mathis Van de Voorde, Oluwafemi S. Ojambati. 2024-11-04. Few photons probe third-order nonlinear properties of nanomaterials in a plasmonic nanocavity. https://arxiv.org/abs/2411.02315

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