Optical manipulation of anisotropic spherical shell particles in a dual-beam trap

In this paper, based on the generalized Lorenz-Mie theory (GLMT), expressions for the scattering coefficient and the shape factor of the beam are derived for a uniaxial anisotropic spherical shell (UASS) particle illuminated by standing laser beams. Through a comprehensive analysis involving the Maxwell stress tensor equations and conservation law of electromagnetic momentum, explicit expressions for both the transverse and axial radiation force (RF) acting upon UASS particles have been analytically derived. The current theories are shown to be valid by comparison with the existing reference. To achieve a more stable capture of UASS particles, the influence of the corresponding parameters of the particle and the dual laser beams on the capture and manipulation is investigated in detail. These investigations could provide an effective way to achieve improvements in optical tweezers and can become an encouraging approach to realize the high accuracy operation of UASS particles.