Non-invasive analysis of turbid samples using deep Raman spectroscopy

Raman spectroscopy has recently seen major advances in the area of deep non-invasive characterisation of diffusely scattering samples; this progress is underpinned by the emergence of spatially offset Raman spectroscopy and associated renaissance of transmission Raman spectroscopy permitting the characterisation of diffusely scattering samples at depths not accessible by conventional Raman spectroscopy. Examples of emerging research activities include non-invasive diagnosis of bone disease and cancer, rapid quality control of pharmaceutical formulations and security screening of explosives and counterfeit drugs through unopened translucent bottles. This article reviews this field focusing on recent developments with high societal relevance.