An holographic microscopy reconstruction method compatible with high numerical aperture microscope objective (MO) up to NA=1.4 is proposed. After off axis and reference field curvature corrections, and after selection of the +1 grating order holographic image, a phase mask that transforms the optical elements of the holographic setup into an afocal device is applied in the camera plane. The reconstruction is then made by the angular spectrum method. The field is first propagated in the image half space from the camera to the afocal image of the MO optimal plane (plane for which MO has been designed) by using a quadratic kernel. The field is then propagated from the MO optimal plane to the object with the exact kernel. Calibration of the reconstruction is made by imaging a calibrated object like an USAF resolution target for different positions along z. Once the calibration is done, the reconstruction can be made with an object located in any plane z. The reconstruction method has been validated experimentally with an USAF target imaged with a NA=1.4 microscope objective. Near-optimal resolution is obtained over an extended range (±50 µm) of z locations.

We study the destabilization mechanism of thin liquid sheets expanding in air and show that dilute oil-in-water emulsion-based sheets disintegrate through the nucleation and growth of holes that perforate the sheet. The velocity and thickness fields of the sheet outside the holes are not perturbed by holes and hole opening follows a Taylor-Culick law. We find that a pre-hole, which widens and thins out the sheet with time, systematically precedes the hole nucleation. The growth dynamics of the pre-hole follows the law theoretically predicted for a liquid spreading on another liquid of higher surface tension due to Marangoni stresses. Classical Marangoni spreading experiments quantitatively corroborate our findings.

The clogging of porous media by colloidal particles is a complex process which relies on many different physical phenomena. The formation and the structure of a clog results from the interplay between hydrodynamics (flow rate and pore geometry) and the DLVO forces (particle–particle and particle–wall). In order to get a better understanding of this process, we study the clogging of a microfluidic filter, at the single pore level, and determine the influence of each relevant parameter separately. We show that in order to form stable clogs, colloidal particles have to pile up over a length in the flow direction roughly equal to the width of the pore. We found that there are two clogging regimes, which depend on the applied pressure. In the first one, at low pressures, the length of the clog within the pore and the number of particles that pass through the pore prior to clogging are constant. In the second one, for higher pressures, both quantities increase with the pressure. We also show that a higher ionic strength accelerates the clog formation, keeping constant the length of the clog

For a droplet or a bubble of dimensions below 100 nm, long-range surface forces such as long-range van der Waals forces can compete with capillarity, which leads to a size dependence of the contact angle. This is discussed in this work, where we also show that the effect cannot simply be described by a normalized line tension. We calculate interfacial profiles for typical values of van der Waals forces and discuss the role of long-range surface forces on the contact angle of nanobubbles and nanodrops.

Heterodyne holography is a variant of phase shifting holography in which reference and signal arms are controlled by acousto optic modulators. We will briefly describe the method and illustrate its advantages on experimental examples.

An holographic laser Doppler scheme using two illumination beams is proposed to image blood vessel in fish embryo. The coincidence of the reconstructed images made for each illumination orientation leads to an accurate z sectioning.

Oil-swollen hexagonal mesophases resulting from the surfactant mediated self-assembly of a quaternarymixture of water, surfactant, co-surfactant, and oil, are versatile templates to synthesize anisotropicnanomaterials. Poly(diphenylbutadyine) (PDPB) polymer nanofibrous network structures were producedin the oil tubes of the mesophases by photo-induced radical polymerization using a chemical initiator orby gamma irradiation. The diameter of the nanofibers can be varied from 5 to 25 nm in a controlledfashion, and is directly determined by the diameter of the oil tube of the doped mesophases, proving thusa direct templating effect of the mesophase. The nanoIR technique allows chemical characterization andidentification of the polymer nanostructures simultaneously with morphological characterization. Cyclicvoltammetry has been used as an effective approach to evaluate both the energy level of the highestoccupied molecular orbital (HOMO) as well as the energy of the lowest unoccupied molecular orbital(LUMO) and the band gap of the PDPB. The conductivity of the PDPB nanostructures obtained by gammairradiation was estimated to be 0.1 S/cm, which is higher than the conductivity of PDPB nanostructurespreviously reported in the literature. The soft template approach allows size tunable synthesis of anisotropicpolymer structures with morphological homogeneity at the nanoscale with high conductivity, thus it appearsto be an attractive opportunity for electronic device applications.