Active Tuning of Plasmon Damping via Light Induced Magnetism
Active Tuning of Plasmon Damping via Light Induced Magnetism
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DOI：
10.1021/acs.nanolett.2c00571
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发表时间：
2022-06-27
期刊：
影响因子：
10.8
通讯作者：
Sheldon, Matthew T.
中科院分区：
文献类型：
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作者：
Cheng, Oscar Hsu-Cheng;Zhao, Boqin;Sheldon, Matthew T.
等离子体纳米结构的圆偏振光激发引起其电子的相干循环运动，这又引起强的光诱导磁化，这是一种被称为逆法拉第效应（IFE）的现象。在这项研究中，我们报告如何IFE也显着降低等离子体阻尼。通过将入射到非手性等离子体纳米结构上的光偏振态从线性调制到圆形，我们观察到在10（9）W/m（2）连续波（CW）光激发下，反射率可逆增加高达8%，同时光场浓度增加35.7%。在存在外部磁场（0.2 T）的情况下，还监测了等离子体激元阻尼降低的这些特征。我们合理化观察到的减少等离子体激元阻尼的洛伦兹力作用于循环电子轨迹。我们的研究结果概述了通过编码在入射光的偏振态的光磁效应主动调制金属中的固有损耗的策略。
Circularly polarized optical excitation of plasmonic nanostructures causes coherent circulating motion of their electrons, which in turn gives rise to strong optically induced magnetization, a phenomenon known as the inverse Faraday effect (IFE). In this study we report how the IFE also significantly decreases plasmon damping. By modulating the optical polarization state incident on achiral plasmonic nanostructures from linear to circular, we observe reversible increases of reflectance by up to 8% and simultaneous increases of optical field concentration by 35.7% under 10(9) W/m(2) continuous wave (CW) optical excitation. These signatures of decreased plasmon damping were also monitored in the presence of an external magnetic field (0.2 T). We rationalize the observed decreases in plasmon damping in terms of the Lorentz forces acting on the circulating electron trajectories. Our results outline strategies for actively modulating intrinsic losses in the metal via optomagnetic effects encoded in the polarization state of incident light.