Apertureless tip-enhanced Raman microscopy with confocal epi-illumination/collection optics.
It is demonstrated that confocal epi-illumination/collection optics can be effectively used to generate surface-enhanced Raman scattering at the near-field region of a gold-coated tip for an atomic force microscope operated in semi-contact tapping mode. When the tip, with a 50-nm apex radius, was illuminated by a highly focused laser beam at 532 nm and approached the isolated diamond particle, with a size of approximately 1 microm, the Raman signal was enhanced by approximately 10(3). This result is in good agreement with numerical simulations performed by the finite difference time-domain method. Since our apertureless microscope is based on readily available conventional components, there is wide room for improvements and modifications by common users in various applications of micro-Raman analysis.
Nanoarchitectonics Research Center, National Institute of Advanced Industrial Science and Technology, Tsukuba Central 4, 1-1-1 Higashi, Tsukuba 305-8562, Japan.
Dmitry S
DS
Bulgarevich
Masayuki
M
Futamata