EN
Scanning Near-Field Optical Microscopy
(SNOM) has developed during recent decades into a
valuable tool to optically image the surface topology of
materials with super-resolution. With aperture-based
SNOM systems, the resolution scales with the size of the
aperture, but also limits the sensitivity of the detection
and thus the application for spectroscopic techniques
like Raman SNOM. In this paper we report the extension
of solid immersion lens (SIL) technology to Raman SNOM.
The hemispherical SIL with a tip on the bottom acts as
an apertureless dielectric nanoprobe for simultaneously
acquiring topographic and spectroscopic information.
The SIL is placed between the sample and the microscope
objective of a confocal Raman microscope. The lateral
resolution in the Raman mode is validated with a
cross section of a semiconductor layer system and, at
approximately 180 nm, is beyond the classical diffraction
limit of Abbe.