Plasmon-Enhanced Second-Harmonic Generation Nanorulers with Ultrahigh Sensitivities

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• 作者：Shaoxin Shen ; Lingyan Meng ; Yuejiao Zhang ; Junbo Han ; Zongwei Ma ; Shu Hu ; Yuhan He ; Jianfeng Li ; Bin Ren ; Tien-Mo Shih ; Zhaohui Wang ; Zhilin Yang ; Zhongqun Tian
• 刊名：Nano Letters
• 出版年：2015
• 出版时间：October 14, 2015
• 年：2015
• 卷：15
• 期：10
• 页码：6716-6721
• 全文大小：428K
• ISSN：1530-6992

文摘

Attainment of spatial resolutions far below diffraction limits by means of optical methods constitutes a challenging task. Here, we design nonlinear nanorulers that are capable of accomplishing approximately 1 nm resolutions by utilizing the mechanism of plasmon-enhanced second-harmonic generation (PESHG). Through introducing Au@SiO₂ (core@shell) shell-isolated nanoparticles, we strive to maneuver electric-field-related gap modes such that a reliable relationship between PESHG responses and gap sizes, represented by 鈥淧ESHG nanoruler equation鈥? can be obtained. Additionally validated by both experiments and simulations, we have transferred 鈥渉ot spots鈥?to the film-nanoparticle-gap region, ensuring that retrieved PESHG emissions nearly exclusively originate from this region and are significantly amplified. The PESHG nanoruler can be potentially developed as an ultrasensitive optical method for measuring nanoscale distances with higher spectral accuracies and signal-to-noise ratios.