SNOM Imaging

alpha 300 RS – Correlative Raman and Scanning Near-Field Optical Microscopy

For the user with challenging experimental requirements, the alpha300 RS facilitates confocal Raman imaging in combination with Scanning Near-field Optical Microscopy for optical imaging with resolution beyond the diffraction limit. It combines all features of the alpha300 S and alpha300 R and many AFM operation modes. Furthermore the combined Raman-SNOM microscope is ideally suited for high-resolution Raman imaging techniques such as nearfield-Raman imaging.

Key Features

  • All features of the alpha300R (Raman) and the alpha300S (SNOW) microscope provided in one instrument
  • Excellent combination of high-resolution surface imaging (SNOW) and chemical imaging (Raman)
  • Ideally suited for combined techniques such as near-field Raman imaging
  • Convenient switching between the measurement techniques is realized by a rotation of the objective turrent
  • Sample movement between the measurements not necessary

Application examples

Left: Topography image of exfoliated graphene simultaneously determined during the nearfield-Raman measurement with corresponding topography curve measured along the blue line. Right: Nearfield-Raman image of the same sample area of the G-band intensity with corresponding intensity graph measured along the red line.

Raman General Operation Modes

  • Raman spectral imaging: acquisition of a complete Raman spectra at every image pixel
  • Planar (x-y-direction) and depth scans (z-direction) with manual sample positioning
  • Image stacks: 3D confocal Raman imaging
  • Time series
  • Single point Raman spectrum acquisition
  • Single-point depth profiling
  • Fibre-coupled UHTS spectrometer specifically designed for Raman microsopy and applications with low light intensities
  • Confocal Fluorescence Microscopy
  • Bright Field Microscopy

Basic Microscope Features

  • Research grade optical microscope with 6x objective turret
  • Video system: video CCD camera
  • High sensitivity b/w video camera to view sample and SNOM/AFM tip in transmission
  • LED white-light source for Köhler illumination of AFM tip and sample
  • Manual sample positioning in x- and y-direction, 25 mm travel
  • Microscope base with active vibration isolation system
  • Fibre coupling
  • Sample size: 120 mm in x- and y-direction, 25 mm in height

SNOW Operation Modes

  • Scanning Near-field Optical Microscopy (SNOM) modes: bottom up and top down mode, collection mode
  • Confocal Microscopy (CM) modes:
    • Transmission
    • Reflection
    • Fluorescence (optional)
    • SNOM-AFM combinations: AFM operation modes of alpha300 A included or optional available
    • Acquisition of force-distance curves and light-distance curves
    • Fixed-bottom illumination
    • Total internal reflection illumination (optional

Raman Optional / Upgradable Operation Modes

  • Additional lasers, several wavelenghts eligible
  • Additional UHTS-spectrometers (UV, VIS, NIR)
  • Automated, motorized sample positioning and measuring with piezo-driven scan stages, 25 mm travel range (50 mm travel range optional)
  • Automated confocal Raman imaging (25 x 25 mm²; optional 50 x 50 mm²)
  • Automated multi-area and multi-point measurements
  • Ultrafast Raman imaging (1300 spectra per second) optional available
  • Upgradable for epi-fluorescence applications
  • Adapter for higher samples
  • TrueSurface for Raman depth profiling
  • Autofocus

AFM Operation Modes

  • Contact Mode
  • Lateral Force Mode
  • others optional

Computer Interface

  • WITec software for instrument and measurement control, data evaluation and processing