Lorenz-Mie scattering of focused light via complex focus fields: An analytic treatment

R. Gutiérrez-Cuevas (1) , Nicole J Moore , Miguel Alonso (2, 3, 4, 5)

1 The Institute of Optics, University of Rochester
2 MOSAIC - MOSAIC
3 FRESNEL - Institut FRESNEL
4 ECM - École Centrale de Marseille
5 AMU - Aix Marseille Université

The Lorenz-Mie scattering of a wide class of focused electromagnetic fields off spherical particles is studied. The focused fields in question are constructed through complex focal displacements, leading to closed-form expressions that can exhibit several interesting physical properties, such as orbital and/or spin angular momentum, spatially varying polarization, and a controllable degree of focusing. These fields constitute complete bases that can be considered as nonparaxial extensions of the standard Laguerre-Gauss beams and the recently proposed polynomials-of-Gaussian beams. Their analytic form turns out to lead also to closed-form expressions for their multipolar expansion. Such expansion can be used to compute the field scattered by a spherical particle and the resulting forces and torques exerted on it, for any relative position between the field’s focus and the particle.

Mots clés: Mie scattering theory; Focused light; Polarization Waves; Mie scattering

Domaines: Optique [physics.optics]

R. Gutiérrez-Cuevas, Nicole J Moore, Miguel Alonso. Lorenz-Mie scattering of focused light via complex focus fields: An analytic treatment. Physical Review A : Atomic, molecular, and optical physics [1990-2015], 2018, 97 (5), ⟨10.1103/PhysRevA.97.053848⟩. ⟨hal-01814151⟩