Directionally enhanced probe for side-illumination Tip enhanced spectroscopy

详细信息    查看全文

• 作者：Hongming Shen ; Guowei Lu ; Zhengmin Cao ; Yingbo He ; Yuqing Cheng ; Jiafang Li ; Zhi-Yuan Li and Qihuang Gong
• 刊名：Journal of Raman Spectroscopy
• 出版年：2016
• 出版时间：October 2016
• 年：2016
• 卷：47
• 期：10
• 页码：1194-1199
• 全文大小：479K
• ISSN：1097-4555

文摘

We investigate the high performance of an apertureless near-field probe consisting of a tapered metal tip with periodic shallow surface grooves. The spontaneous emission of a single emitter near the apex is systematically analyzed for side-illumination tip enhanced spectroscopy scheme. In contrast to a conventional bare tapered tip, the corrugated probe not only strongly enhances the local excitation field, but also modulates the emission directivity, leading to high collection efficiency and signal-to-noise ratio. Specifically, we propose that an asymmetric tip enhanced spectroscopy probe containing two different length nanorods at the apex realizes unidirectional emissions. The radiation pattern is sensitive to the emission wavelengths and the emitter positions, which can increase the signal-to-noise ratio through suppression of the undesired signal. The proposed asymmetrical corrugated probe possesses a wide range of potential applications, including increasing the detection efficiency of tip enhanced spectroscopy at the single molecule level. Copyright