Establishment of an optical trapping curve for prediction of trapping parameters

Abstract

Optical trapping is widely used to manipulate a small-sized particle freely suspended in the isotropic fluidic domain. Trapping is done by means of optical forces developed by conversing light beam. The active gradient forces, depends upon parameters like light wavelength, particle size, and refractive index of medium and particle. The viscous drag forces, depends upon parameter like viscosity of fluid, relative velocity of particle with respect to medium. The necessary condition for particle trapping is to maintain > . In this paper, a graphical approach is applied to predetermine the value of specific parameter such as relative velocity of particle and light wavelength under the necessary condition for optical trapping, while keeping other parameters are as fixed. Software simulation is performed with set of relative velocities on polystyrene small-sized particle in water channel to validate the graphical approach