Publications

@article{Dooley2022-rt,

title = {Model-based optimization of laser excitation and detection 

 improves spectral contrast in noninvasive diffuse Raman 

 spectroscopy},

author = {Max Dooley and Thomas Paterson and Louise Dexter and Pavel Matousek and Hamid Dehghani and Ioan Notingher},

year  = {2022},

date = {2022-07-01},

journal = {Appl. Spectrosc.},

volume = {76},

number = {7},

pages = {801\textendash811},

publisher = {SAGE Publications},

abstract = {Spatially offset Raman spectroscopy (SORS) is a powerful 

 technique for subsurface molecular analysis of optically turbid 

 samples. Numerical modeling of light propagation has been used 

 to investigate opportunities for improving spectral contrast and 

 signal to noise ratio when imaging regions of interest located 

 0-4.5 mm below the surface in polymer bulk material. Two- and 

 three-dimensional modeling results demonstrate that when 

 analyzing a certain region of interest (ROI) of finite lateral 

 dimensions below the sample surface, offsetting both the laser 

 source and detector in opposite directions from the central 

 point of the ROI can increase the spectral contrast as compared 

 to conventional SORS approach where the detector or the laser 

 source is maintained at the central point (centered SORS). The 

 outlined modeling results have been validated experimentally 

 using a bulk polymer sample with a trans-stilbene ROI (cylinder) 

 below the sample surface. The results show that modeling of the 

 spatial configurations of laser excitation and detection points 

 can be used to optimize the instrument configuration to achieve 

 significant improvements (up to 2.25-fold) in performance over 

 the conventional centered SORS. Such optimal solutions can then 

 be implemented, for example, using robust fiber optic probes, 

 moveable optics, or flexible spatial light modulator instruments 

 for specific applications.},

keywords = {computational modeling, diffuse Raman, Raman spectroscopy, SORS, spatially offset Raman spectroscopy},

pubstate = {published},

tppubtype = {article}

}