Evaluation of a multimode fiber optic low coherence interferometer for path length resolved Doppler measurements of diffuse light.
The performance of a graded index multimode fiber optic low coherence Mach-Zehnder interferometer with phase modulation is analyzed. Investigated aspects were its ability to measure path length distributions and to perform path length resolved Doppler measurements of multiple scattered photons in a turbid suspension of particles undergoing Brownian and translational motion. The path length resolution of this instrument is compared with a system using single mode fibers for illumination and detection. The optical path lengths are determined from the zero order moment of the phase modulation peak in the power spectrum. The weighted first moment, which is equal to the average Doppler shift, shows a linear response for different mean flow velocities within the physiological range.
Varghese
Babu
B
Institute for Biomedical Technology, Biophysical Engineering Group, University of Twente, P.O. Box 217, NL-7500AE Enschede, The Netherlands. b.varghese@utwente.nl
Rajan
Vinayakrishnan
V
Van Leeuwen
Ton G
TG
Steenbergen
Wiendelt
W
D001783:Blood Flow Velocity / Q000502:physiology*; D004867:Equipment Design; D019544:Equipment Failure Analysis; D005336:Fiber Optic Technology / Q000295:instrumentation*; D007368:Interferometry / Q000295:instrumentation*; D017078:Laser-Doppler Flowmetry / Q000295:instrumentation*; D008027:Light; D055100:Optical Fibers; D015203:Reproducibility of Results; D012542:Scattering, Radiation; D012680:Sensitivity and Specificity; D041623:Tomography, Optical Coherence / Q000295:instrumentation*