Crouzier Marius, Mao Fei, Magno Giovanni, Yam Vy, Alonso-Ramos Carlos, Coudevylle Jean-René, Herth Etienne, Dupuis Christophe, Leroux Xavier, Lopez Thomas, Dagens Béatrice
Université Paris-Saclay, CNRS, Centre de Nanosciences et de Nanotechnologies, Palaiseau, 91120, France.
Centre technique de Vélizy, Stellantis, Vélizy-Villacoublay, 78140, France.
Sci Rep. 2025 Jul 1;15(1):22072. doi: 10.1038/s41598-025-05446-7.
Plasmonic nanoparticles can concentrate energy at the nanometer scale, offering promising applications across multiple fields such as lab-on-chip technologies and photonic circuits. A crucial requirement for these applications is achieving efficient coupling between the nanoparticles and the excitation signal. Plasmonic nanoparticle chains can guide light at subwavelength scale and can be excited through coupling to a dielectric waveguide. In this manuscript, we propose a novel configuration for the plasmonic chain-dielectric waveguide structure that allows the chain to be freely positioned relative to the waveguide. We demonstrate the existence of a critical coupling regime between a silicon waveguide and a plasmonic chain, achieved through precise control of their separation. In this regime, the plasmonic chain transitions from its well-known transmission mode to a new cavity state, trapping 99% of the waveguide's energy. This result paves the way for efficiently addressing nanostructures through integrated waveguides, enabling efficient optical nano-tweezers, sensors or nano-heaters.
等离子体纳米颗粒可以在纳米尺度上集中能量，在诸如芯片实验室技术和光子电路等多个领域提供了有前景的应用。这些应用的一个关键要求是实现纳米颗粒与激发信号之间的有效耦合。等离子体纳米颗粒链可以在亚波长尺度上引导光，并且可以通过与介质波导耦合来激发。在本论文中，我们提出了一种用于等离子体链 - 介质波导结构的新颖配置，该配置允许链相对于波导自由定位。我们通过精确控制硅波导和等离子体链之间的间距，证明了它们之间存在临界耦合状态。在这种状态下，等离子体链从其众所周知的传输模式转变为一种新的腔态，捕获了波导99%的能量。这一结果为通过集成波导有效寻址纳米结构铺平了道路，从而实现高效的光学纳米镊子、传感器或纳米加热器。
