@article{moffitt02e,
  author = {Theodore P. Moffitt and Scott A. Prahl},
  title = {In Vivo Determination of Optical Properties of Skin in the {UV} Using Sized-Fiber Reflectometry},
  journal = {Laser Med. Surg.},
  year = {2002 abstract only},
  volume = {S14},
  pages = {3},
  abstract = {The purpose is to determine the absorption and reduced scattering coefficients of human skin in vivo for wavelengths 250--400\,nm using a sized-fiber device. The method involves sized-fiber reflectance measurements that use two different diameter fibers at 200 and 600 microns, which independently emit and collect light. Reflectances for each fiber are converted to the absorption and reduced scattering coefficient based on Monte Carlo simulations. The device is validated using phantoms with known optical properties. Because the source fiber is also used to collect its emitted light, highly localized measurements of tissue are possible. Larger diameter fibers collect more light from deeper in the tissue. A device with 200 and 600 micron fibers collects light that travel less than 5 reduced mean free paths into the tissue. However for a 600 micron fiber, half of the returning photons travel less than 1.9 reduced mean free paths. For the 200 micron, this depth drops to 1.3 mean free paths. Due to the small sampling depth of this sized-fiber device, in vivo optical property measurements of the epidermis are possible with minimal interference from the dermis. We measured the optical properties of the epidermis of 10 individuals in vivo from 250--400\,nm from the ventral side of the forearm. At 400\,nm in wavelength, a typical reduced mean free path is 50 microns for human skin. Mineral oil is applied to the skin to fill voids in the stratum corneum. Results are presented as the wavelength dependent absorption and reduced scattering coefficients for the individuals where skin tones range from very fair to very dark skin. A comparison of our results and published ex vivo measurements is presented. We conclude with the advantages and disadvantages of localized fiber measurements and demonstrate the capability of this technique to determine optical properties at short wavelengths.},
}