Compact design for robust tip-enhanced nano-spectroscopy in ambient conditions

Abstract

Nano-spectroscopy and -imaging based on scanning probe microscopy, such as tip-enhanced photoluminescence and tip-enhanced Raman spectroscopy, allow us to investigate various quantum materials with a spatial resolution of $<$10 nm. Although the correlation between topography and nano-spectroscopic response provides distinct material information compared to other optical measurement methods, acquiring high-speed and high-resolution nano-spectroscopic images under ambient conditions remains challenging. One major obstacle is the drift between optical and mechanical components, which causes image distortion and decoupling between the tip and excitation laser, thereby limiting the precision of near-field information. Here, we present a compact design for a homebuilt tip-enhanced nano-spectroscopy system and demonstrate its building with pre-characterization results. The setup is based on an atomic force microscope utilizing a quartz tuning fork as a force sensor. Its compact 6 cm-sized body provides ample space for optical access. This design achieves a low lateral drift rate between the tip and sample, measured at less than 0.65 nm/min, enabling stable nano-spectroscopic measurements of various quantum materials.