A simple procedure for the recovery of deep subsurface Raman spectra in stratified turbid samples by defocusing a conventional Raman instrument is presented. The method is based on effects present with spatially offset Raman spectroscopy (SORS) and, although not as efficient as the standard SORS approach, it permits a simple way of recovering subsurface Raman spectra from less challenging samples. Demonstration of the effect is performed using a standard SORS device and a commercial Raman instrument on the noninvasive measurement of paracetamol tablets held within a nontransparent white plastic bottle.
Vol. 2, Iss. 11 Virtual Journal for Biomedical Optics
C. Eliasson, M. Claybourn, and P. Matousek, "Deep Subsurface Raman Spectroscopy of Turbid Media by a Defocused Collection System," Appl. Spectrosc. 61, 1123-1127 (2007)