Scaling and analyzing the influence of fluid surface of fluid with nano-granular through speckle pattern experiment

Abstract

An optical system with double beam interference system was designed to measure the movement of nano-particles in fluid with laser speckle technology. In order to investigate the influence of the scattering light generated from liquid surface on speckle patterns, the liquid surface contour was dynamically detected by WYKO during nano-particle movement. The result demonstrates that the fluctuation of fluid surface is slight. Meanwhile, in order to further analyze this effect, a piece of ground glass was employed. The process of ground glass to be polished to optical glass was studied and tested continuously using WYKO and laser speckle technology. And then, the speckle patterns generated from kerosene fluid surface were studied. By contrast, the results show that, the fluid surface is transparent to the measurement wavelength. The influence of the surface of fluid can be neglected. Furthermore, the conclusion illustrates that laser speckle technique is an effective and reliable method to study the movement of nano-granular in fluid.