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Updated: Oct 10, 2026

A Multimodal Wide-Field Fourier-Transform Raman Microscope
Published on: December 30, 2025
Electric field gradient effects in raman spectroscopy
E J Ayars1, H D Hallen, C L Jahncke
1Physics Department, North Carolina State University, Raleigh, North Carolina 27695-8202, USA.
Abstract:
Raman spectra of materials subject to strong electric field gradients, such as those present near a metal surface, can show significantly altered selection rules. We describe a new mechanism by which the field gradients can produce Raman-like lines. We develop a theoretical model for this "gradient-field Raman" effect, discuss selection rules, and compare to other mechanisms that produce Raman-like lines in the presence of strong field gradients. The mechanism can explain the origin and intensity of some Raman modes observed in SERS and through a near-field optical microscope (NSOM-Raman).
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