nano-FTIR (nanoscale FTIR) is a powerful combination of s-SNOM equipped with broadband illumination and FTIR-based detection developed by neaspec. nano-FTIR provides infrared spectroscopy at the spatial resolution of AFM, delivering nanoscale chemical identification and hyperspectral imaging.

Basic Working Principle: 

  1. focus broadband IR beam onto a sharp AFM tip;
  2. illuminated tip creates a strong nano-focus at its apex;
  3. nano-focus acts as a ultra-small “white light” source that probes spectral properties of a sample through near-field optical interaction, which modifies tip-scattered light.
  4. FTIR detection recovers both amplitude and phase of the tip-scattered light, delivering complete spectral response of the sample (e.g. both absorption and reflectivity).

nano-FTIR principle

Challenge: Broadband illumination requires a method for recording spectrally-resolved amplitude (reflectivity) and phase (absorption) of the broadband scattered light, while completely suppressing parasitic background. A strong light source with large spectral bandwidth is also needed to achieve nano-FTIR spectroscopy with sufficient spectral coverage in a single shot.

nano-FTIR was developed and patented by neaspec and is the only technology that can simultaneously detect broadband near-field amplitude and phase spectra with 100% background suppression.

nano-FTIR is based in on a s-SNOM setup comprising an asymmetric interferometer where the AFM tip and the sample are located in one of the interferometer arms. Broadband source (e.g. laser, synchrotron, etc.) illuminates the AFM tip. Tip-scattered light is recombined with the reference beam at the detector. The detector signal is recorded as a function of reference mirror position, creating an (asymmetric) interferogram. Fourier transformation of this interferogram returns the local amplitude and phase spectra, which relate to the sample reflectivity and absorption.

List of other neaspec’s patented s-SNOM detection technologies that provide 100% background suppression:
  • PsHet (Pseudo-Heterodyne): golden standard for nanoscale imaging and spectroscopy.
  • P-Spec: PsHet-quality s-SNOM point spectroscopy by laser sweeping.
  • HSH (High-Speed Holography): fastest imaging method for screening of large sample areas with the best S/N quality of all known s-SNOM imaging methods.

Compare different s-SNOM technologies and learn why neaspec is the market leader.

neaspec nano-FTIR provides:

  • Absorption spectra directly comparable to standard FTIR databases for nanoscale chemical identification
  • 10 nm spatial resolution with standard AFM tips throughout the whole IR spectrum disregarding the materials type or morphologynano-FTIR line scan on purple membrane
  • Covers the whole mid-IR fingerprint and functional group spectral region for complete chemical characterization
  • Widest spectral bandwidth of up to 200cm-1 available in a single shot without distorting stitching artefacts for accurate chemical analysis
  • Best-in-class sensitivity, detecting single monolayers and even individual macromolecules, e.g. ferritin
    nano-FTIR spectra of Ferritin
  • Spectrally averaged nanoscale imaging for quick sample screening to identify features of interest for subsequent spectral analysis and chemical ID
    Chemical Identification using nano-FTIR
  • Access to the dielectric function at the nanoscale, i.e. refractive index and attenuation coefficient
    nano-FTIR ellipsometry
  • Broadband hyperspectral imaging for ultimate chemometric analysis at the nanoscale
    nano-FTIR hyperspectral imaging

Advantages & Strengths of neaspec nano-FTIR and Hyperspectral Imaging

Purely Optical

Reliable direct optical measurements independent from tip-sample mechanics and properties

FTIR Principles

Absorption spectroscopy and chemical ID using well-established FTIR principles

True Broadband

Continuous spectrum at every pixel (vs. multiple spectral points) for reliable quantitative analysis based on peak ratios & widths

Highest Versatility

Works for all materials – absorbing or not – and in all spectral ranges (from visible to sub-THz)

Analytical Technique

Analytical

Provides access to refractive index and absorption coefficient for ultimate chemometric analysis

Ultra-broadband source

Largest Bandwidth

Exclusive femtosecond source optimized for large bandwidth spectroscopy without stitching artefacts

Subsurface analysis

Subsurface

Capable of spectroscopic surface and subsurface analysis

Ultrafast pump-probe

Pump-Probe Ready

Can be upgraded to provide ultrafast pump-probe spectroscopy at the nanoscale

synchtrotron ready

Synchrotron Ready

The only successful nano-spectroscopy proven to work with synchrotron radiation

Download E-Books