The Influence of Parameters of the Dielectric and Fluid on Usefulness of the Optical Trap Ho Quang Quy1, Hoang Dinh Hai2, Phan Si Chau3, Do Ich Tinh3, Doan Hoai Son3, Mai Van Luu31 Institute of Applied Physics, NEWTECHPRO, VAST, 8 Hoang Quoc Viet, Hano, Vietnam. hoquy1253@yahoo.com2Pedagogical College of Nghe An, Vietnam.3Faculty of Physics, Vinh University, Vietnam.Abstract: In this article the stable process of the dielectric particle in optical trap is investigated. The influence of the mechanical parameters as the radius of dielectric particle, viscosity of surrounding fluid on the usefulness of optical trap using pulsed Gaussian beam is simulated and discussed.Key words: Optical trap, Pulsed Gaussian beam, Optical force, Brownian motion.1. IntroductionIn 1970, Ashkin [1] first demonstrated the optical trapping of particles using the radiation force produced by the focused continuous-wave (CW) Gaussian beam. Since then the optical trap and tweezers has been a powerful tool for manipulating dielectric particles [2, 3].In works [4-7], the discussions about stability of the...