Low-coherence self-referencing velocimetry
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Updated: Jul 15, 2026

Meso-Scale Particle Image Velocimetry Studies of Neurovascular Flows In Vitro
Published on: December 3, 2018
Andreas Kempe1, Stefan Schlamp, Thomas Rösgen
1Institute of Fluid Dynamics, ETH Zürich, Zürich, Switzerland. kempe@ifd.mavt.ethz.ch
Abstract:
Low-coherence self-referencing velocimetry optically measures the relative velocity between a point in a particle-laden fluid and a (potentially moving) reference surface. Low-coherence light scattered off the particles and off the reference surface is coupled into an interferometer with variable optical delay in one arm and an acousto-optical modulator in the second arm. The measurement location is set relative to the reference surface. Its location can be scanned along a line by adjusting the optical delay in the interferometer. The spatial resolution is typically tens of micrometers. Only one low-coherence light beam is required for each component of the velocity vector. Proof-of-principle measurements in Taylor-Couette flow are presented.
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