Nano-FTIR Spectroscopy

Neaspec’s Patented Optical Near-Field Detection Enables Visible, IR & Even THz Imaging & Spectroscopy @ 10nm Spatial Resolution.

The spatial resolution of conventional optical microscopes is limited by diffraction to about half the wavelength (Abbe diffraction limit). neaspec broke the diffraction limit by developing the neaSNOM microscope, a groundbreaking apertureless near-field microscope (known as scattering-type Scanning Near-field Optical Microscopy, s-SNOM) that combines Atomic Force Microscopy with optical imaging and spectroscopy at the nanoscale.

This opens a new era for modern nano-analytical applications such as chemical nano-identification (IR), nano-plasmonic field mapping (VIS & IR) or free charge carrier nano-mapping (THz).

neaSNOM employs standard metal-coated AFM probing tips (T), illuminated by a focused laser beam (L). Illuminated tips generate a nano-focus (N) at their apex, used as an ultra-small light source to locally probe the sample. The size of the nano-focus is determined only by the radius of the tip apex. This is true even for electromagnetic waves much longer than the visible light, like infrared and terahertz radiation, yielding the same spatial resolution of 10 nm throughout the optical spectrum.

Development of a dedicated Fourier-transform detection module for analyzing light scattered from the AFM tip which is illuminated by a broadband laser source enabled IR spectroscopy of complex nanostructures (nano-FTIR).

Optical imaging is performed by detecting the backscattered light interferometrically (optical amplitude & phase are acquired simultaneously) while scanning the sample surface topography. By illuminating the AFM-tip with a broadband infrared laser, an IR-spectrum of a 10nm spot is recorded (nano FTIR).

The neaSNOM microscope combined with imaging & spectroscopy systems from neaspec thus allow to study chemical, structural and electronic properties of a sample @ a spatial resolution up to 1000-times higher when compared to conventional technology like micro FT-IR.