New Method for Determination of Surface Potential of Microscopic Particles by Second Harmonic Generation
نویسندگان
چکیده
A new noninvasive method for determining the surface electrostatic potential and surface charge density of microscopic particles using second harmonic generation (SHG) is described. The surface electrostatic properties of 1.05 μm polystyrene sulfate spheres in aqueous solution and that of 0.22 μm oil droplets in aqueous emulsions are obtained. Comparisons of the surface potentials obtained from SHG with the zeta potential obtained from electrophoresis are in excellent agreement with theoretical predictions.
منابع مشابه
A New Method for Characterization of Biological Particles in Microscopic Videos: Hypothesis Testing Based on a Combination of Stochastic Modeling and Graph Theory
Introduction Studying motility of biological objects is an important parameter in many biomedical processes. Therefore, automated analyzing methods via microscopic videos are becoming an important step in recent researches. Materials and Methods In the proposed method of this article, a hypothesis testing function is defined to separate biological particles from artifact and noise in captured v...
متن کاملSecond harmonic generation from the surface of centrosymmetric particles in bulk solution
Second harmonic generation (SHG) is reported for the first time from the surfaces of centrosymmetric particles in bulk isotropic solution. Although SHG is generally described as electric dipole forbidden in centrosymmetric systems, we show that this requires the system to be centrosymmetric on length scales much less than the coherence length of the process. This condition is not satisfied for ...
متن کاملStudy of the Transition to Instability in Second-Harmonic Generation with Scale Index Method
The emergence of second-harmonic generation (SHG) is a pivotal issue to the development of nano-optical devices and interfaces. Here, we perform a classical analysis of the SHG dynamics with the aim of determining critical values of the electric field. The signals of the SHG process are nonlinear, so it seems reasonable that chaos theory can be a suitable tool to analyze their dynamics. For thi...
متن کاملGalerkin Finite-Element Method for the Analysis of the Second Harmonic Generation in Wagon Wheel Fibers
The nonlinear effects of the second harmonic generation have been investigated for the propagation of light along the axis of fibers of wagon wheel cross sectional shape. Nodal finite element formulation is utilized to obtain discretized Helmholtz equations under appropriate boundary conditions. The hierarchical p-version nodal elements are used for meshing the cross section of wagon wheel fibe...
متن کاملConsiderably Enhanced Second-Harmonic Generation in Resonant U-Shaped Nano-Structures
In this paper, we perform a detailed study of the spectral response of the gold U-shaped nano-structures for different geometrical parameters and polarizations in order to obtain significant localization factor in the wavelength 1.55 μm. The obtained near-field distribution of electric fields reveals that resonances in these nano-structures correspond to the even and odd plasmonic modes dependi...
متن کامل