Design of ILIDS configurations for droplet characterization

3D-Tracking of Sand Particles in a Wave Flume Using Interferometric Imaging

“…The determination of this z-coordinate is thus reduced to the determination of the ellipticity of the defocused interferometric image. For droplets in air or bubbles in water, the z-position of the particle can be further coupled to a rotation of the orientation of interference fringes to enhance the accuracy [27,28]. This is not possible with rough particles such as sand, whose interferometric images are complex speckle patterns.…”

“…Another possibility is to use a cylindrical defocused imaging system. The longitudinal position of the particle is then linked to the ellipticity of the defocused image of the particle [27][28][29], and specific algorithms can be developed to determine the ellipticity of the defocused images [34]. This last solution based on a cylindrical imaging configuration is tested in the present work.…”

“…IPI delivers 2D images. To perform a 3D-tracking of particles and to obtain in particular their longitudinal position, a solution is to build a cylindrical imaging system [27][28][29][30][31][32]. It still works in a defocused configuration.…”

Determination of the Size of Irregular Particles Using Interferometric Out-of-Focus Imaging

“…Their coefficients depend on the coefficients of optical transfer matrices describing the optical elements encountered between the particle and the sensor. The procedure has been detailed in references [7,16] in the case of droplets represented by a pair of Dirac emitters and has been validated in all cases that could be tested experimentally [7,17,18]. For a unique Dirac emitter, we obtain the following expression of the electric field in the plane of the CCD sensor [7]:…”

“…2 ( 2 + 3 ) is the optical path between the plane of the aperture and the plane of the CCD sensor. In ILIDS, it has been shown that a droplet can be well represented by two emitters [7,16]. Let us now consider the case of a multiemitter composed of gp Dirac emitters randomly located on a half sphere, as shown in Figure 3(a).…”