Scattering delay time of Mie scatterers determined from steady-state and time-resolved optical spectroscopy

J Opt Soc Am A Opt Image Sci Vis. 2000 Apr;17(4):745-9. doi: 10.1364/josaa.17.000745.


We have determined the scattering delay time of Mie scatterers (r = 255 nm quartz spheres in polyester resin) from a combination of steady-state (integrating-sphere) and time-resolved (frequency-domain) measurements performed in the multiple-scattering regime. The effective transport velocity of light was derived from intensity and phase measurements at four different wavelengths by using the time-integrated microscopic Beer-Lambert law. We could demonstrate a systematic underestimation of the effective transport velocity compared with the phase velocity in the medium. Assuming that this discrepancy was caused entirely by the transient nature of a single-scattering process, the data presented resulted in time delays of between 18 fs (lambda = 678 nm) and 177 fs (lambda = 1,064 nm) per scattering event. For three out of four wavelengths investigated, the measured values are in excellent agreement with values predicted by a theoretical model for the scattering delay time based on Mie theory.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Light*
  • Models, Theoretical*
  • Optics and Photonics*
  • Photons
  • Scattering, Radiation
  • Time Factors