Measuring the speed and direction of vortices is of great importance in fluid dynamics. We report on the use of a CW laser beam with a superposition of Laguerre-Gaussian (LG) modes generated by a phase mask imprinted on a two-dimensional spatial light modulator. The shaped beam is then guided and scattered of a sample which is rotated; the rotational frequency is extracted from spectral analysis of the scattered light. This method allows for virtually real-time determination of vorticity characterization in a fluid.

Date Published: 3 March 2015
PDF: 6 pages
Proc. SPIE 9343, Laser Resonators, Microresonators, and Beam Control XVII, 93431G (3 March 2015); doi: 10.1117/12.2080238

Published in SPIE Proceedings Vol. 9343:
Laser Resonators, Microresonators, and Beam Control XVII
Alexis V. Kudryashov; Alan H. Paxton; Vladimir S. Ilchenko; Lutz Aschke; Kunihiko Washio, Editor(s)