Raman spectroscopy gives details about the molecular structure of samples on the basis of the characteristic vibrational modes of the molecule. It can be used to identify a variety of materials (minerals, pigments, organics etc.) and the fact that it is completely non-destructive makes it extremely attractive for the analysis of invaluable objects, such as artworks and archaeological objects.

Our mobile Raman microspectrometer (Exemplar Plus, ΒWTEK) uses a cw (continuous wave) diode laser working at 785 nm as excitation source. An optical probe head focusses the laser beam onto the sample surface by means of a set of objective lenses offering different levels of magnification. A white LED and a digital colour camera are included on the optical head, which allow visualization of the object’s surface and selection of the area (spot) to be analyzed. The spectrometer provides high spectral resolution (< 8 cm−1) and sensitivity, covering a spectral range between 100 – 3300 cm−1. The employed detector (Peltier-cooled) features high sensitivity with low dark counts.