Heterodyne speckle velocimetry
Abstract
We present a simple method for fluid velocimetry based on the velocity of the heterodyne speckles generated by tracking particles illuminated with coherent light. It works in real time and provides instantaneous two-dimensional velocity mappings in the direction orthogonal to the optical axis, independently of the particle concentration and size, also for subwavelength particles. It also provides the velocity distribution of the fluid over the entire sample thickness. The method has been quantitatively tested by using the motions of rigid diffusers and applied for mapping the flow of a confined fluid.
- Publication:
-
Applied Physics Letters
- Pub Date:
- May 2006
- DOI:
- 10.1063/1.2200396
- Bibcode:
- 2006ApPhL..88s1101A
- Keywords:
-
- 47.80.Jk;
- 47.80.Cb;
- 06.30.Gv;
- 07.60.Ly;
- Flow visualization and imaging;
- Velocity measurements;
- Velocity acceleration and rotation;
- Interferometers