Fiber bundle micro-SORS portable prototype: a new solution for Heritage Science

In fifteen words or less, explain the significance of this contribution (Novel Aspect).: Innovative portable micro-SORS prototype enables non-invasive, in-depth analysis of cultural heritage artifacts on-site.

Abstract Text:

Recently, an advanced portable Raman spectrometer has been developed at the Raman Spectroscopy Laboratory of CNR-ISPC, in collaboration with University of Cincinnati [1]. This non-conventional prototype enables the deployment of micro-SORS method [2] in an innovative way. Its unique feature lies in the integration of a micrometric fibre bundle within the Raman collection path. This configuration preserves the spatial offset information on the detector, allowing the simultaneous acquisition of Raman photons from both surface and subsurface layers in separate spectra.

This device represents a technological advancement since the use of the fibre bundle eliminates the need for manually setting individual spatial offsets; this significantly enhances stability and simplifies the technique’s application for in-situ measurements. These characteristics make it a particularly valuable tool in the field of Cultural Heritage, where non-invasive analysis is essential due to the uniqueness and fragility of the artworks involved.

Furthermore, Cultural Heritage materials often consist of heterogeneous and complex mixtures of compounds. Much of the critical information regarding artist’s materials, techniques, and the conservation history is often hidden beneath the surface, making it crucial to access information from a certain volume of the object. The prototype combines non-invasiveness, portability, and depth sensitivity in a single, versatile instrument.

Following its development, the spectrometer has been used in several analytical campaigns in museums, aimed at collecting data to deepen our understanding of artefact histories. This is achieved through the study of material composition, enabling the reconstruction of historical contexts and assessment of conservation state. In this presentation, we outline the advantages and limitations of employing this prototype in museum settings, with a particular focus on archaeological finds.

Among the most significant results are the reconstruction of painted layer sequences and the detection of decay products that are randomly distributed on the surface—compounds that would otherwise remain undetected by conventional systems due to their small crystalline size. However, limitations of the technique include reduced spatial resolution, which poses challenges in distinguishing very thin surface layers.

 

[1] A Lux et al., Analyst 149 (8), 2317-2327, 2024.

[2] S Mosca et al., Nature Reviews Methods Primers 1 (1), 21, 2021.