Abstract

A recently developed micrometer-scale spatially offset Raman spectroscopy (μ-SORS) method provides a new analytical capability for investigating non-destructively the chemical composition of sub-surface, micrometer-scale thickness, diffusely scattering layers at depths beyond the reach of conventional confocal Raman microscopy. Here, we demonstrate experimentally, for the first time, the capability of μ-SORS to determine whether two detected chemical components originate from two separate layers or whether the two components are mixed together in a single layer. Such information is important in a number of areas, including conservation of cultural heritage objects, and is not available, for highly turbid media, from conventional Raman microscopy, where axial (confocal) scanning is not possible due to an inability to facilitate direct imaging within the highly scattering sample. This application constitutes an additional capability for μ-SORS in addition to its basic capacity to determine the overall chemical make-up of layers in a turbid system.

© 2015 The Author(s)

Femtosecond pulse laser cleaning of spray paint from heritage stone surfaces

J. Brand, A. Wain, A. V. Rode, S. Madden, P. L. King, and L. Rapp
Opt. Express 30(17) 31122-31135 (2022)

TeraHertz imaging of hidden paint layers on canvas

Aurèle J. L. Adam, Paul C. M. Planken, Sabrina Meloni, and Joris Dik
Opt. Express 17(5) 3407-3416 (2009)

Optical coherence tomography and non-linear microscopy for paintings – a study of the complementary capabilities and laser degradation effects

Haida Liang, Meropi Mari, Chi Shing Cheung, Sotiria Kogou, Phillip Johnson, and George Filippidis
Opt. Express 25(16) 19640-19653 (2017)

Hyperspectral spatially offset Raman spectroscopy in a microfluidic channel

Moritz Matthiae and Anders Kristensen
Opt. Express 27(3) 3782-3790 (2019)

DMD-based software-configurable spatially-offset Raman spectroscopy for spectral depth-profiling of optically turbid samples

Zhiyu Liao, Faris Sinjab, Graham Gibson, Miles Padgett, and Ioan Notingher
Opt. Express 24(12) 12701-12712 (2016)