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A Random-displacement Measurement by Combining a Magnetic Scale and Two Fiber Bragg Gratings
Published on: September 30, 2019
Laser-Doppler velocity profile sensor with submicrometer spatial resolution that employs fiber optics and a
Lars Büttner1, Jürgen Czarske, Hans Knuppertz
1Professorship for Measuring and Testing Techniques, Dresden University of Technology, D-01062 Dresden, Germany. buettner@iee.et.tu-dresden.de
Abstract:
We report a novel laser-Doppler velocity profile sensor for microfluidic and nanofluidic applications and turbulence research. The sensors design is based on wavelength-division multiplexing. The high dispersion of a diffractive lens is used to generate a measurement volume with convergent and divergent interference fringes by means of two laser wavelengths. Evaluation of the scattered light from tracers allows velocity gradients to be measured in flows with submicrometer spatial resolution inside a measurement volume of 700-microm length. Using diffraction optics and fiber optics, we achieved a miniaturized and robust velocity profile sensor for highly resolved velocity measurements.

