Polarization Transfer from the Twisted Light to an Atom

Abstract

When polarized light is absorbed by an atom, the excited atomic system carries information about the initial polarization of light. For the light that carries an orbital angular momentum, or the twisted light, the polarization states are described by eight independent parameters, as opposed to three Stokes parameters for plane waves. We use a parameterization of the spin-density matrix of the twisted light in terms of vector and tensor polarization, in analogy with massive spin-1 particles, and derive formulae that define atom's response to specific polarization components of the twisted light. It is shown that for dipole ($S\to P$) atomic transitions, the atom's polarization is in one-to-one correspondence with polarization of the incident light; this relation is violated, however, for the transitions of higher multipolarity ($S\to D$, $S\to F$, etc.) We pay special attention to contributions of the longitudinal electric field into the matrix elements of atomic transitions.

arXiv comment9 pages, 4 figures; one figure added. Version accepted in J. Opt

References in corpus (7)

• Generation of High-Energy Photons with Large Orbital Angular Momentum by Compton Backscattering
• Off-axis excitation of hydrogenlike atoms by twisted photons
• Twisted-ligth--ion interaction: the role of longitudinal fields
• Experimental Verification of Position-Dependent Angular-Momentum Selection Rules for Absorption of Twisted Light by a Bound Electron
• Atomic Spectroscopy with Twisted Photons: Separation of M1--E2 Mixed Multipoles
• Novel Properties of Twisted-Light Absorption
• Modification of multipole transitions by twisted light

Cited by in corpus (5)

• Recoil Momentum Effects in Quantum Processes Induced by Twisted Photons
• Trapped atoms in spatially-structured vector light fields
• Theoretical consideration of a twisted atom
• Topology and Polarization of Optical Vortex Fields from Atomic Phased Arrays
• Conversion of twistedness from light to atoms