title: Resonance Raman measurements of carotenoids using light-emitting diodes.
abstract: We report on the development of a compact commercial instrument for measuring carotenoids in skin tissue. The instrument uses two light-emitting diodes (LEDs) for dual-wavelength excitation and four photomultiplier tubes for multichannel detection. Bandpass filters are used to select the excitation detection wavelengths. The f1.3 optical system has high optical throughput and single photon sensitivity, both of which are crucial in LED-based Raman measurements. We employ a signal processing technique that compensates for detector drift and error. The sensitivity and reproducibility of the LED Raman instrument compares favorably to laser-based Raman spectrometers. This compact, portable instrument is used for noninvasive measurement of carotenoid molecules in human skin with a repeatability better than 10%.
authors.affiliation: Brigham Young University, Department of Physics Astronomy, Provo, Utah 84602, USA. scott.bergeson@byu.edu
authors.forename: Scott D
authors.initials: SD
authors.lastname: Bergeson
authors.forename: Justin B
authors.initials: JB
authors.lastname: Peatross
authors.forename: N Jay
authors.initials: NJ
authors.lastname: Eyring
authors.forename: John F
authors.initials: JF
authors.lastname: Fralick
authors.forename: Douglas N
authors.initials: DN
authors.lastname: Stevenson
authors.forename: Scott B
authors.initials: SB
authors.lastname: Ferguson
mesh_terms: D002338:Carotenoids / Q000032:analysis*; D046169:Dermoscopy / Q000295:instrumentation*; D004867:Equipment Design; D019544:Equipment Failure Analysis; D006801:Humans; D008029:Lighting / Q000295:instrumentation*; D008904:Miniaturization; D012666:Semiconductors; D012867:Skin / Q000378:metabolism*; D013059:Spectrum Analysis, Raman / Q000295:instrumentation*
chemical_list: D002338:Carotenoids