title: Controlling the optical path length in turbid media using differential path-length spectroscopy: fiber diameter dependence.
abstract: We have characterized the path length for the differential path-length spectroscopy (DPS) fiber optic geometry for a wide range of optical properties and for fiber diameters ranging from 200 microm to 1000 microm. Phantom measurements show that the path length is nearly constant for scattering coefficients in the range 5 mm(-1)< micros <50 mm(-1) for all fiber diameters and that the path length is proportional to the fiber diameter. The path length decreases with increasing absorption for all fiber diameters, and this effect is more pronounced for larger fiber diameters. An empirical model is formulated that relates the DPS path length to total absorption for all fiber diameters simultaneously.
authors.affiliation: Center for Optical Diagnostics and Therapy, Department of Radiation Oncology, Erasmus Medical Centre Rotterdam, Rotterdam, The Netherlands. a.amelink@erasmusmc.nl
authors.forename: O P
authors.initials: OP
authors.lastname: Kaspers
authors.forename: H J C M
authors.initials: HJ
authors.lastname: Sterenborg
authors.forename: A
authors.initials: A
authors.lastname: Amelink
mesh_terms: D000465:Algorithms; D004867:Equipment Design; D019544:Equipment Failure Analysis; D005336:Fiber Optic Technology / Q000295:instrumentation* / Q000379:methods; D007089:Image Enhancement / Q000295:instrumentation* / Q000379:methods; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D009391:Nephelometry and Turbidimetry / Q000295:instrumentation* / Q000379:methods; D055100:Optical Fibers; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D041623:Tomography, Optical Coherence / Q000295:instrumentation* / Q000379:methods