Abstract

By using different types of structured light, a Gaussian and a Bessel beam, as illumination for single or multiple particles assumed by a Lorentzian polar- izability a selective excitation is investigated. This topic is based on previous research done in the area of light-matter interactions [6], where four plane waves are used to control the electric and magnetic multipole moments of an atomic cloud. Introducing the angular spectrum representation of both beams, a di- rect computation of the scattered electrical fields by an aggregate of spheres is possible using the T-matrix approach [2]. Furthermore, the different character- istics of both beams are discussed by investigating their field distributions. It is shown that different aspects of both beams, for the Gaussian beam its waist and for the Bessel beam the angular momentum, can be used to achieve a selective excitation of a two particle system.
[1] Akbar Safari Rasoul Alaee and Robert W. Boyd. Selective excitation of subwave- length atomic clouds. Physical Review Research, 3(023217), 2021
[2] Yu lin Xu. Electromagnetic scattering by an aggregate of spheres. Applied Optics, 34(4573-88), 1995.