title: Angular measurements of light scattered by turbid chiral media using linear Stokes polarimeter.
abstract: The effects of turbid chiral media on light polarization are studied in different directions around the scattering samples using a refined linear Stokes polarimeter, which simplifies the signal analysis, and allows for the detailed investigations of scattered light. Because no moving parts are involved in a measurement at a specific detection direction, the determination accuracy of polarization states is increased. The results show that light depolarization increases with both turbidity and detection angle for low and moderately turbid samples; however, the angular dependence decreases with increasing turbidity. When the turbidity is increased to approximately 100 cm(-1), the depolarization becomes higher in the forward than in the backward direction. Polarization sensitive Monte Carlo simulations are used to verify some experimental observations. The results also demonstrate that surviving linear polarization fraction and overall intensity are more sensitive to the increase of glucose concentration in backward than in the forward direction in highly turbid media, indicating that backward geometry may be preferable for potential glucose detection in a biomedical context. Comparison measurements with optically inactive glycerol suggest that the refractive index matching effect, and not the chiral nature of the solute, dominates the observed optical rotation engendered by glucose in highly turbid media.
authors.affiliation: Ontario Cancer Institute, Division of Biophysics and Bioimaging and University of Toronto, Department of Medical Biophysics, 610 University Avenue, Toronto, Ontario M5G 2M9, Canada.
authors.forename: Xinxin
authors.initials: X
authors.lastname: Guo
authors.forename: Michael F G
authors.initials: MF
authors.lastname: Wood
authors.forename: I Alex
authors.initials: IA
authors.lastname: Vitkin
mesh_terms: D004867:Equipment Design; D019544:Equipment Failure Analysis; D005240:Feasibility Studies; D008027:Light; D008859:Microscopy, Polarization / Q000295:instrumentation* / Q000379:methods; D009391:Nephelometry and Turbidimetry / Q000295:instrumentation* / Q000379:methods; D019047:Phantoms, Imaging; D012031:Refractometry / Q000295:instrumentation* / Q000379:methods; D015203:Reproducibility of Results; D012399:Rotation; D012542:Scattering, Radiation; D012680:Sensitivity and Specificity