title: Near-Field Raman Spectroscopy with Aperture Tips.
abstract: In this paper, we review nano-Raman techniques based on aperture scanning near-field optical microscopy (SNOM). Fundamentals of SNOM and aperture-tip-based near-field Raman spectroscopy and their applications in key technical issues, including Raman signal intensity and collection time, are introduced. Recent advances in the tip design are discussed, and applications of the aperture-SNOM-based nano-Raman technique are presented. We attempt to identify the most pressing open questions in this field. We believe that, by improving the power transmission efficiency and combining the local field enhancing technique with the tip-enhanced spectroscopy, the performance of aperture-SNOM can be significantly improved. Its nanometer-scale excitation volume and the consequent low background make the aperture-tip technique feasible for many important samples that cannot be measured by other optical nanospectroscopies.
authors.affiliation: College of Engineering and Applied Sciences, National Laboratory of Solid State Microstructures, and Collaborative Innovation Center of Advanced Microstructures, Nanjing University , Nanjing 210093, China.
authors.forename: Weihua
authors.initials: W
authors.lastname: Zhang
authors.affiliation: School of Physics, State Key Lab for Mesoscopic Physics, and Collaborative Innovation Center of Quantum Matter, Peking University , Beijing 100871, China.
authors.forename: Zheyu
authors.identifier: http://orcid.org/0000-0001-5780-0728
authors.initials: Z
authors.lastname: Fang
authors.affiliation: School of Physics, State Key Lab for Mesoscopic Physics, and Collaborative Innovation Center of Quantum Matter, Peking University , Beijing 100871, China.
authors.forename: Xing
authors.initials: X
authors.lastname: Zhu