Mini‐Review: Angular Scattering and Directional Effects in Tip‐Enhanced Raman Spectroscopy

ABSTRACT Tip‐enhanced Raman spectroscopy (TERS) enables molecular vibrational spectroscopy with subnanometer resolution. Although TERS mechanisms and applications continue to be actively explored, the spatial characteristics of far‐field TERS emission, which are critical for quantitative interpretations, reproducibility, and cross‐comparison, have received comparatively less attention. Moreover, although tip orientation and shape are routinely considered, the influences of individual setup configurations on far‐field collection efficiency are often overlooked in data analysis, particularly when comparing experimental results across different research groups. Recent angularly resolved TERS studies have revealed spatial variations in far‐field emission for both photoluminescence and Raman scattering. These findings suggest that spatially selective far‐field signal collection schemes can significantly compromise spectral interpretation in TERS. Given these considerations, this review summarizes fundamental geometries and optical polarization techniques employed in TERS and links them to plasmonic interactions between the tip, the sample, and the substrate. In conclusion, it elucidates how these factors influence the far‐field response. Special emphasis is placed on recent experimental and theoretical work concerning optically excited TERS signal and its angular emission.