Raman Spectroscopy
Raman spectroscopy:
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gives very specific material identification by comparing the Raman spectrum obtained with spectra of known materials,
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can be used with complementary techniques such as XRF or FORS in close range, or VIS-NIR and SWIR reflectance spectral imaging at close or remote range, for a more comprehensive identification of a material,
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can operate at distances of a few centimetres at laser wavelengths of 532 nm and 785 nm.
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can be used in the spatial offset mode or in the micro-Raman mode.
Combined Raman and FORS providing close analysis of a map at the National Gallery as part of the From Lima to Canton research project. Here the instrument is mounted on a large elevated stage, allowing the lens to be repositioned without moving or placing pressure on the map.
The ISAAC Research Centre has developed a number of mobile Raman spectrometers for both close range and remote operation at large stand-off distances up to 14m.
Close range Raman spectroscopy extends the working distance of mobile Raman spectroscopy from centimetres up to tens of metres. Mobile close range micro Raman spectroscopy operates at distances of a few centimetres at laser wavelengths of 532 nm and 785 nm.
Remote Raman spectroscopy extends the working distance to tens of metres and can be used to conveniently analyse any spot on a monument/object from the ground level without having to move the instrument. Given the non-invasive nature of the technique, it can also be used for mapping a small region remotely (macro-Raman mapping).
Remote Raman scanning of the hunting frieze on the tomb of Philip II in Vergina, Greece.
Applications of Raman Spectroscopy
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Non-invasive, highly specific identification of inorganic materials (e.g. pigments, salts) on works of art and architectural monuments.
isaac instrumentation
Close Range Raman Spectroscopy
System
Micro Raman
Spatially Offset Raman
Developer
ISAAC Lab
ISAAC Lab
Excitation Wavelength
532 nm
785 nm
Spectral Range (Raman Shift)
30 – 2620 cm-1
90 – 3050 cm-1
Spot Size
1 µm
20 µm
Working
Distance
5 mm
50 mm
Service
MOLAB/
FIXLAB
MOLAB/
FIXLAB
Remote Raman Spectroscopy
System
Remote Raman
Developer
ISAAC Lab
Excitation Wavelength
785nm
Spectral Range (Raman Shift)
90 – 3050 cm-1
Spot Size
1mm
Working
Distance
3m – 20 m
Service
MOLAB/
FIXLAB
example heritage science projects
selected publications
This is a selection of our Raman Spectroscopy publications. Our full publication list can be found here.
Kogou, S., Li, Y., Cheung, S., Han, N., Liggins, F., Shahtahmassebi, G., Thickett, D. and Liang, H. 2025 Ground-Based Remote Sensing and Machine Learning for in Situ and Noninvasive Monitoring and Identification of Salts and Moisture in Historic Buildings. Analytical Chemistry 2025 https://doi.org/10.1021/acs.analchem.4c05581
Li, Y., Suzuki, A., Cheung, C.S., Kogou, S. & Liang, H., 2024. Ground-Based Remote Standoff Laser Spectroscopies and Reflectance Spectral Imaging for Multimodal Analysis of Wall Painting Stratigraphy. Analytical Chemistry, 96, 47, 18907-18915 https://doi.org/10.1021/acs.analchem.4c05264
Li, Y., Suzuki, A., Cheung, C., Gu, Y., Kogou, S. & Liang, H., 2022. A Study of Potential Laser-Induced Degradation in Remote Standoff Raman Spectroscopy for Wall Paintings. The European Physics Journal Plus, 137, 1102. https://doi.org/10.1140/epjp/s13360-022-03305-2
Li, Y., Cheung C. S., Kogou, S. Hogg, A., Liang, H. and Evans, S. 2021. Standoff Laser Spectroscopy for Wall Paintings, Monuments and Architectural Interiors. In Transcending Boundaries: Integrated Approaches to Conservation. ICOM-CC 19th Triennial Conference Preprints, Beijing, 17–21 May 2021, ed. J. Bridgland. Paris: International Council of Museums. ISBN 9782491997144
Li, Y., Cheung C. S., Kogou, S., Liggins, F., and Liang, H., 2019. Standoff Raman Spectroscopy for Architectural Interiors from 3-15m Distances. Optics Express, 27(22), 31338-31347 https://doi.org/10.1364/OE.27.031338