Radiation force and torque exerted on a stratified sphere in the circularly polarized TEM_01*-mode laser beam

Abstract

An expression of the circularly polarized TEM01∗-mode laser beam is obtained from the vector potential A, of which the scalar part becomes a linear combination of the complex multipole fields with the orders of (1, 0) and (0, 1). A light-scattering theory of the TEM01∗-mode laser beam by a stratified sphere is developed, and the -analytic formulas are derived for the radiation force and torque on a stratified particulate sphere located anywhere in the TEM01∗-mode laser beam. Numerical calculations of the radiation force and torque are presented for a singlelayered sphere case. The z-components of radiation force Fz and radiation torque Trot,z on a transparent hollow sphere with r1 = 0.5λ, r2 = 2.0λ in radii and N2 = 1.5 + i0.001 in refractive index are found to be 2 × 10−9 (dyne) and 0.75 × 10−14 (dyne cm), respectively, for a 1-W TEM01∗-mode laser beam.