Quantitative Analytical Model for Scattering-type Scanning Near-field Optical Spectroscopy
arXiv:2508.16365 · doi:10.1002/adom.202501539
Abstract
Scattering-type scanning near-field optical microscopy (s-SNOM) is a versatile technique in nanooptics, enabling local probing of optical responses beyond the diffraction limit from vis to THz frequencies. Its theoretical modeling based on tip-sample interactions typically relies on computationally intensive numerical methods or phenomenological models with empiric fitting parameters, complicating spectral analysis and interpretation. Developing a rigorous quantitative analytical model remains a significant challenge in near-field microscopy. Here, we introduce an accurate analytical solution for the prolate spheroid model of s-SNOM in the quasi-electrostatic limit. We validate our solution through comparisons with numerical simulations and experimental spectra. Due to its higher computational efficiency compared to numerical simulation and higher accuracy compared to phenomenological solutions, our solution for spheroid model facilitates spectrum prediction and interpretation for homogeneous bulk samples, enables systematic exploration of parameter effects, and supports data generation for machine learning applications. Furthermore, the generality of our approach allows straightforward extension to more complex nanostructures.
27 pages, 9 figures, including Supporting Information
References in corpus (14)
- Gate-tuning of graphene plasmons revealed by infrared nano-imaging
- Model for quantitative tip-enhanced spectroscopy and the extraction of nanoscale-resolved optical constants
- Probes for Ultrasensitive THz Nanoscopy
- Near-field spectroscopy of silicon dioxide thin films
- Understanding the image contrast of material boundaries in IR nanoscopy reaching 5 nm spatial resolution
- Graphene-Based Platform for Infrared Near-Field Nanospectroscopy of Water and Biological Materials in an Aqueous Environment
- Generalized spectral method for near-field optical microscopy
- Quantifying nanoscale electromagnetic fields in near-field microscopy by Fourier demodulation analysis
- Substrate matters: Surface-polariton enhanced infrared nanospectroscopy of molecular vibrations
- Hybrid Machine Learning for Scanning Near-field Optical Spectroscopy
- Scattering of electromagnetic waves from a cone with conformal mapping: application to scanning near-field optical microscope
- Cryogenic Magneto-Terahertz Scanning Near-field Optical Microscope (cm-SNOM)
- High sensitivity variable-temperature infrared nanoscopy of conducting oxide interfaces
- Images of point charges in conducting ellipses and prolate spheroids