The instrument which is under development is a non-conventional portable Raman spectrometer. Raman spectrometers provide the molecular composition of the material surfaces, essential for their identification. The instrument peculiarity relies in the simultaneous acquisition of Raman spectra at imaged position and at different micrometric distances (offset) from the laser illumination area. Spectra acquired at the imaged position provide information about the molecular composition of the material surface, whereas in the spectra collected at offset distances there is a higher percentage of Raman photons coming from the inner portions. The micrometric spatial resolution of the instrument allows investigating in a non-invasive way and in-situ the compounds located below the surface at a depth range from a few tens to hundreds of micron.
The instrument has never been developed neither by Research Institutions nor by companies. A portable instrument optimized at the millimetric scale (SORS) is developed by Agilent for pharmaceutical and security applications; however, the under development instrument differs for the micrometric scale range of investigation (micro-SORS); the extension of the technique to the micrometric range needs the development of a deeply different technology if compared with that used for portable SORS and the applicability to fields not already explored by conventional SORS. In the non-invasive instruments scenario, the instrument is unique since it is able to provide the molecular composition of the compounds located below the surface, not only their optical properties or elemental composition, thus allowing a unequivocal identification of the target compounds.