Spatially offset Raman microspectroscopy of highly scattering tissue: theory and experiment

Abstract

Spatially Offset Raman Spectroscopy (SORS) has seen considerable interest in recent years as a tool for noninvasively acquiring Raman spectra from beneath the surface of a sample. One of the major limitations of the SORS technique is that accurate knowledge of the optical properties of the medium is required to translate an offset into a sample depth. We report on the benefits of preforming SORS using micron offset distances as opposed to the more typical millimeter offsets used. Monte Carlo simulations are used to demonstrate that at these small offsets, the results depend less on the scattering coefficient of the material. These results provide new insights into the SORS technique and will improve the practical application of SORS in the future.

Keywords:

• Raman spectroscopy
• light propagation in tissues
• photon migration

Acknowledgements

We gratefully acknowledge the support of the National Science Foundation Grants PHY-1241032 (INSPIRE CREATIV), PHY-1068554, EEC-0540832 (MIRTHE ERC), PHY-1205868, PHY-1307153, ECCS-1250360, DBI-1250361, and CBET-1250363, and the Robert A. Welch Foundation (Awards A-1261, grant A1547). H.C. is supported by the Herman F. Heep and Minnie Belle Heep Texas A&M University Endowed Fund held/administered by the Texas A&M Foundation.