We calculate trapping forces, trap stiffness and interference effects for spherical particles in optical tweezers using electromagnetic theory. We show the dependence of these on relative refractive index and particle size. We investigate resonance effects, especially in high refractive index particles where interference effects are expected to be strongest. We also show how these simulations c...

High-permittivity dielectric particles with resonant magnetic properties are being explored as constitutive elements of new metamaterials and devices. Magnetic properties of low-loss dielectric nanoparticles in the visible or infrared are not expected due to intrinsic low refractive index of optical media in these regimes. Here we analyze the dipolar electric and magnetic response of lossless d...

Particles in protein therapeutics, composed of aggregated protein monomers, may cause an immunogenic response in patients. Consequently, industry and the FDA desire more accurate methods for counting and characterizing particles. Unlike many manufacturing impurities, protein particles have a refractive index very close to that of the matrix solution. In this paper, we describe some of the measu...

the engineering properties of soils are generally affected by parameters such as mineral type, structure, and pore water salinity. the existing solutes of soil play a role in the electrochemical forces between particles and can change the index and mechanical properties of soil, including cohesion, compressibility, and compactibility. this study investigated the effect of sodium chloride, sodiu...

We describe a new measurement technique to determine the refractive index (RI) of solid particles by monitoring simultaneous scattering light from suspension with camera and value RI refractometer. Our immersion matching method is based on solidification process liquid continuously changing as function time. The principle determination finding point particle during solidification. traditional s...

expansive behavior is usually observed in soils, which contain fractions of clay minerals in their composition. water absorption of clay particles and change of natural water content of soil up to plastic limit and down to shrinkage limit will cause significant volume change in expansive soils and will result in severe damages to the structures, buildings and foundations. swelling potential is ...

We introduce a background-free real-time detection scheme capable of recognizing low-index nanoparticles such as single viruses in water. The method is based on interferometrically measuring the electromagnetic field amplitude of the scattered light. A split detector is used to generate a background-free signal that renders unprecedented sensitivity for small particles. In its current configura...