arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 1604.02249physics.optics
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利用高Q微腔中的耗散作用探测单个纳米粒子

Detection of Single Nanoparticles Using the Dissipative Interaction in a High-Q Microcavity

Bo-Qiang Shen, Xiao-Chong Yu, Yanyan Zhi, Li Wang, Donghyun Kim, Qihuang Gong, Yun-Feng Xiao

摘要:

纳米尺度颗粒的超灵敏光学检测对于人类疾病的早期诊断、环境监测和国土安全中的应用是非常期望的,但由于小尺寸、低折射率颗粒的超低极化率而仍然非常困难。光学回音壁模式微腔可以显著增强光与物质的相互作用,是一种很有前途的纳米级物体无标记检测平台。不同于依赖于电抗(即,色散)相互作用,在这里,我们提出并证明了检测单个有损纳米粒子使用的耗散相互作用在高$Q$环形微腔。在实验中,通过同时监测腔模的线宽变化和位移,实现了对单个金纳米棒在水环境中的检测。实验结果符合理论预测。值得注意的是,通过设置探测波长打开和关闭表面等离子体共振来调节纳米棒的吸收,来评估反应性和耗散感测方法,这清楚地证明了耗散感测方法检测有损耗纳米颗粒的巨大潜力。未来的应用还可以结合耗散和反应传感方法,这可能会提供更好的表征纳米颗粒。

英文摘要:

Ultrasensitive optical detection of nanometer-scaled particles is highly desirable for applications in early-stage diagnosis of human diseases, environmental monitoring, and homeland security, but remains extremely difficult due to ultralow polarizabilities of small-sized, low-index particles. Optical whispering-gallery-mode microcavities, which can enhance significantly the light-matter interaction, have emerged as promising platforms for label-free detection of nanoscale objects. Different from the conventional whispering-gallery-mode sensing relying on the reactive (i.e., dispersive) interaction, here we propose and demonstrate to detect single lossy nanoparticles using the dissipative interaction in a high-$Q$ toroidal microcavity. In the experiment, detection of single gold nanorods in an aqueous environment is realized by monitoring simultaneously the linewidth change and shift of the cavity mode. The experimental result falls within the theoretical prediction. Remarkably, the reactive and dissipative sensing methods are evaluated by setting the probe wavelength on and off the surface plasmon resonance to tune the absorption of nanorods, which demonstrates clearly the great potential of the dissipative sensing method to detect lossy nanoparticles. Future applications could also combine the dissipative and reactive sensing methods, which may provide better characterizations of nanoparticles.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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