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Spatially Offset Raman Spectroscopy (SORS™) is a unique way to analyse objects when the contents is behind non-transparent layers or container materials

SORS vs. Conventional Raman

SORS is a unique variant of Raman spectroscopy that was invented at the Science and Technology Facilities Council’s (STFC) Rutherford Appleton Laboratory by a group including Cobalt founding director and Chief Scientific Officer, Prof Pavel Matousek.

SORS works through many millimetres of material, enabling accurate chemical analysis through barriers such as paper, glass, plastic, fabric and skin. The method requires no prior knowledge of the container/surface material and does not require direct physical contact.

Conventional Raman spectroscopy is limited to surfaces or is reliant on transparency of packaging/coatings for analysis of sub-surface composition. This means that the majority of containers need to be opened in order to identify the contents.

How SORS Works

SORS uses multiple measurements – but usually just two – to determine the spectrum of a container’s contents. A “conventional” Raman measurement, where the laser illumination and light collection are coincident, yields a signal which is usually dominated by the container material. A spatially offset measurement, where the excitation and collection are separated, contains greater Raman contribution from the contents. A scaled subtraction of the two measurements creates a clean spectrum of the contents for easy identification.

Zero offset and spatially offset spectra produce a clean contents spectrum

Zero offset and spatially offset spectra produce a clean contents spectrum

SORS Applications

SORS has been applied already to many problems (see the Products and Knowledge sections in the further reading links at the bottom of this page), but the ability to quickly and easily analyse and identify materials through non-transparent containers has wide-ranging applications. Cobalt’s SORS products currently include:

  • Insight100™ - Screening containers for explosives in airport security checks
  • RapID™ - Raw materials identification in pharmaceutical quality control

SORS applications include:

  • Explosive/Hazardous substance detection for military personnel and emergency responders
  • Detection of counterfeit products
  • Screening of packages for safety and customs use
  • Non-invasive biomedical screening

If you have a need for chemical analysis through barriers and would like to discuss the potential benefits of SORS technology, get in touch at