Aerosol Structure Measured By Double Field Of View Digital Sideband Holography

Digital sideband in-line holography is a technique, based in classical digital in-line holography, that allows the measurement of the position and velocity of the particles in a three dimensional fluid flow. The great advantage of this technique is its very simple set-up, which basically requires a camera, a lens and a frequency filter to record the holograms. The sideband configuration removes the twin image and prevents the recording of unwanted frequencies that causes aliasing, therefore increasing the Signal-to-Noise Ratio. In this work it has been applied for the quantitative characterization of a three-dimensional aerosol, where droplet velocity and position have been measured. The field of view that can be recorded with magnification M≈1 has been doubled by illuminating two volumes with the same beam that crosses the aerosol twice before reaching the camera sensor. These two fluid volumes are analyzed independently while keeping a high spatial resolution in the axial component.