Scanning Near-field Optical Microscope (SNOM)

Scanning near-field optical microscopy (SNOM) provides optical imaging beyond the diffraction limit. It positions an optical probe close to the surface with an atomic force microscope (AFM) controller and uses the near-field response to image the surface. The light source (a 532-nanometer laser) on our tool also has an inverted optical microscope, a spectrometer, and a manually operated stage for spatial and confocal Raman imaging. 

Typical Applications

  • Ideally suited for quickly and effortlessly imaging the optical properties of a sample with resolution below the diffraction limit because it requires minimal sample preparation 
  • Nanotechnology research, particularly in nano-photonics and nano-optics 
  • Determination of surface and near-surface chemistry via Raman spectroscopy 
  • Single molecule detection is easily achievable using fluorescence techniques 

Instruments

W I T E C alpha 300 S S N O M
WITEC alpha300 S SNOM 
  • Micro-fabricated cantilever SNOM sensors 
  • Aperture size typically 100 nm, other optional 
  • Standard AFM cantilever probes 
  • Beam-deflection distance control for SNOM and AFM 
  • Low noise, highly focused optics for beam deflection laser 
  • No interference with excitation laser
  • Ultra-low laser noise 
  • Near-field mode 100 nm, depending on aperture size; confocal mode typically 200 nm diffraction-limited

 

 

Instrument Contact: Stephen Golledge, PhD