ABSTRACT
Objects illuminated by light will be subject to a force generated by optical radiation. Since it usually appears as pressure, it is called light pressure. The single-beam optical gradient force trap has many advantages, such as accurate position control, high trapping ability, and a wide range of applications. The Rayleigh model is usually applied in analyzing the optical trapping force on particles much smaller than the wavelength of light. The model of trapping force on microsphere near focus in single optical tweezers is built by the three-dimensional Finite Difference Time Domain and Maxwell stress tensor methods. The trapping capacities on nanoscale-diameter nanowires are discussed in terms of a strongly focused linearly polarized beam and radially polarized beam. In the Rayleigh model, the force of the electric dipole in an electromagnetic field can be divided into two components: scattering force and gradient force.
