Active Far-Field Control of the Thermal Near-Field via Plasmon Hybridization
Active Far-Field Control of the Thermal Near-Field via Plasmon Hybridization
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DOI：
10.1021/acsnano.9b04968
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发表时间：
2019-08-01
期刊：
影响因子：
17.1
通讯作者：
Masiello, David J.
中科院分区：
文献类型：
--
作者：
Bhattacharjee, Ujjal;West, Claire A.;Masiello, David J.
在纳米尺度上控制和操纵温度的能力有可能影响热辅助磁记录、光热疗法和温度驱动反应性等应用。在纳米尺寸控制温度的一项挑战是需要减轻热扩散，使得温度仅在样品的明确纳米级区域发生变化。在这里，我们展示了使用远场激光激发通过共振泵浦同相或异相杂化偶极等离子体模式来主动塑造单个金纳米棒异二聚体中的热近场的能力。使用单粒子光热外差成像，我们证明了由于一对纳米棒中的一个纳米棒的优先加热而导致的光热强度的局部偏差。理论建模和数值模拟明确了所得光热图像如何编码异二聚体中每个纳米棒之间的波长依赖性温度偏差，证明了通过简单地调整入射光颜色来主动管理热近场的能力。
The ability to control and manipulate temperature at nanoscale dimensions has the potential to impact applications including heat-assisted magnetic recording, photothermal therapies, and temperature-driven reactivity. One challenge with controlling temperature at nanometer dimensions is the need to mitigate heat diffusion, such that the temperature only changes in well-defined nanoscopic regions of the sample. Here we demonstrate the ability to use far-field laser excitation to actively shape the thermal near-field in individual gold nanorod heterodimers by resonantly pumping either the in-phase or out-of-phase hybridized dipole plasmon modes. Using single-particle photothermal heterodyne imaging, we demonstrate localization bias in the photothermal intensity due to preferential heating of one of the nanorods within the pair. Theoretical modeling and numerical simulation make explicit how the resulting photothermal images encode wavelength-dependent temperature biases between each nanorod within a heterodimer, demonstrating the ability to actively manage the thermal near-field by simply tuning the color of incident light.