近日，意大利拉奎拉大学Andrea Marini团队研究了极紫外Epsilon近零非线性增强。该研究于2025年10月27日发表在《光：科学与应用》杂志上。

具有消失介电常数的材料为实现等离子体增强光-物质相互作用提供了理想的平台，并广泛应用于各种前沿非线性光子学应用。

在这项工作中，研究组提出了极紫外（XUV）等离子体增强自驱动光谱修饰亚微米铝箔的第一个实验演示。这是通过激发具有极低吸收的广泛可调谐的费雷尔-伯里曼ε -近零共振来实现的。研究组对光谱调制增强的角度相关测量结果得到了理论分析的支持，揭示了峰值强度低至380 GW/cm²时的有效光谱修饰，研究组将其归因于超快加热和饱和效应。这些发现标志着通过非线性等离子体增强XUV区典型弱非线性方面的突破，有望为操纵和控制XUV辐射的前所未有的工具铺平道路。

附：英文原文

Title: Epsilon-near-zero nonlinearity enhancement in the extreme ultraviolet

Author: Ferrante, Carino, Principi, Emiliano, Assogna, Luca, Sahoo, Ambaresh, Batignani, Giovanni, Fumero, Giuseppe, Foglia, Laura, Mincigrucci, Riccardo, Giannessi, Luca, Scopigno, Tullio, Masciovecchio, Claudio, Marini, Andrea

Issue&Volume: 2025-10-27

Abstract: Materials with a vanishing dielectric constant provide an ideal platform for achieving plasmon-enhanced light-matter interactions and are widely employed in various cutting-edge nonlinear photonics applications. In this study, we present the first experimental demonstration of extreme ultraviolet (XUV) plasmon-enhanced self-driven spectral modification using a submicrometric foil of aluminium. This is achieved through the excitation of widely tunable Ferrell-Berreman epsilon-near-zero resonances with extremely low absorption. Our angle-dependent measurements of spectral modulation enhancement, supported by theoretical analysis, reveal efficient spectral modification at peak intensities as low as 380 GW/cm2, which we attribute to ultrafast heating and saturation effects. These findings mark a breakthrough in the enhancement of typically weak nonlinearities in the XUV regime through nonlinear plasmonics, potentially paving the way for unprecedented tools for the manipulation and control of XUV radiation.

DOI: 10.1038/s41377-025-01985-w

Source: https://www.nature.com/articles/s41377-025-01985-w