We report a novel laser-Doppler velocity profile sensor for microfluidic and nanofluidic applications and turbulence research. The sensor's 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-µm length. Using diffraction optics and fiber optics, we achieved a miniaturized and robust velocity profile sensor for highly resolved velocity measurements.
© 2005 Optical Society of America
(050.1970) Diffraction and gratings : Diffractive optics
(120.0120) Instrumentation, measurement, and metrology : Instrumentation, measurement, and metrology
(120.3180) Instrumentation, measurement, and metrology : Interferometry
(280.3340) Remote sensing and sensors : Laser Doppler velocimetry
Lars Büttner, Jürgen Czarske, and Hans Knuppertz, "Laser-Doppler velocity profile sensor with submicrometer spatial resolution that employs fiber optics and a diffractive lens," Appl. Opt. 44, 2274-2280 (2005)