Optical torque on an absorptive dielectric sphere of arbitrary size illuminated by a linearly-polarized Airy light-sheet

Abstract

Based on the generalized Lorenz-Mie theory (GLMT) and the angular spectrum decomposition method (ASDM), we calculate the time-averaged optical (spin) torque (OST) exerted on an absorptive dielectric sphere of arbitrary size illuminated by a TM polarized Airy light-sheet, and the negative optical torque is particularly emphasized. The influence of the transverse scale parameter w0 and attenuation parameter γ of the Airy light-sheet on the torque is discussed. The numerical results show that both w0 and γ have impact on the amplitude and spatial distributions of the OST. Furthermore, the OST amplitude depends on the position of the sphere in the transverse plane of wave propagation. In addition, the OST for a TE-polarized Airy light-sheet illuminating the absorptive dielectric sphere vanishes due to some symmetry considerations related to the vertical polarization property of the electric field vector. The results are of some practical significance for the development of Airy light-sheet based optical rotation of a suspended particle in light-sheet tweezers.