Optical communications allow high-rate and long-distance digital data transmission using optical fibers, lasers and optical amplifiers. Although this is on of the main applications, optical communications have more, such as the scientific study of artworks using laser technology.
The Optical Communications Group from UPC in Barcelona investigates and work with photonic technologies to analyse the pigments used in art objects. A few months ago I had the opportunity to visit their research laboratory and I also assisted in a lecture about the analysis of pigments using Raman Spectroscopy, which I will try to summarize.
Analysis of pigments with Raman Spectroscopy
Raman Spectroscopy is a photonic technique that allows to unequivocally characterize a chemical compound, providing a signal known as Raman Spectrum. It is a non-invasive and non-destructive technique, which is the main reason why it is used to identify the constituent materials in artworks. When illuminated with a pulsed ultraviolet laser, it emits a special frequency in the Raman spectra, which can be analysed to identify the pigments.
Analysing the Raman spectra we can identify the pigments used, ascertain the artist’s palette. If we know the period of utilization and the date of appearance of each pigment we can successfully discover the period when it was painted. With this information we can also establish the possible authorship of the work. For example, the next oil and canvas dated from 1930 was initially attributed to Joaquín Torres García. However, the identified pigments are Rutile (1940) and Violet 23 (1960) so we can conclude that it is a fake!
- Raman Spectroscopy group from UPC
- The Scientific Study of Artworks Using Laser-Raman Technology (Spanish)