Assessment of photon migration in scattering media using heterodyning techniques with a frequency modulated diode laser.
A novel technique for studying photon propagation in scattering media is proposed and demonstrated, as is believed, for the first time. Photons propagating through the medium, from a frequency-ramped single-mode diode laser, meet a reference beam from the same source, at a common detector, and beat frequencies corresponding to various temporal delays are observed by heterodyne techniques. Fourier transformation directly yields the temporal dispersion curve. Proof-of-principle experiments on polystyrene foam and a tissue phantom suggest, that the new method, when fully developed, may favorably compete with the more complex time-correlated single-photon counting (TCSPC) and the phase-shift methods, now much employed.
Guan
Zuguang
Z
Atomic Physics Division, Lund University, P.O. Box 118, S-22100 Lund, Sweden. Zuguang.Guan@fysik.lth.se
Lundin
Patrik
P
Svanberg
Sune
S