Spin-to-orbital angular momentum conversion in focusing, scattering, and imaging systems.
نویسندگان
چکیده
We present a general theory of spin-to-orbital angular momentum (AM) conversion of light in focusing, scattering, and imaging optical systems. Our theory employs universal geometric transformations of non-paraxial optical fields in such systems and allows for direct calculation and comparison of the AM conversion efficiency in different physical settings. Observations of the AM conversions using local intensity distributions and far-field polarimetric measurements are discussed.
منابع مشابه
Mechanical generation of spin current
Spin current, a flow of spins, is a key concept in the field of spintronics. It is generated by using angular momentum conversion among magnetic angular momentum due to magnetization dynamics, photon angular momentum, angular momentum due to orbital motion of electron, and spin angular momentum [1–3]. Meanwhile, mechanical angular momentum carried by condensed matter systems due to macroscopic ...
متن کاملElectromagnetic Form Factors and the Localization of Quark Orbital Angular Momentum in the Proton
Deeply inelastic scattering experiments contradict the notion that the proton’s spin is the sum of the spins of the quarks. The s-wave non-relativistic bound state picture of the proton has then been ruled out. Consequently there is great interest in the orbital angular momentum of quarks and the spin of gluons. While the spin of gluons is difficult to define gauge invariantly, the orbital angu...
متن کاملAngular momentum of a strongly focused Gaussian beam
A circularly polarized paraxial Gaussian laser beam carries ±h̄ angular momentum per photon as spin, with zero orbital angular momentum. Focusing the beam with a rotationally symmetric lens cannot change this angular momentum flux, yet the focused beam must have spin |Sz | < h̄ per photon. The remainder of the original spin is converted to orbital angular momentum, manifesting itself as a longitu...
متن کاملTheory of orbital state and spin interactions in ferromagnetic titanates
A spin-orbital superexchange Hamiltonian in a Mott insulator with t2g orbital degeneracy is investigated. More specifically, we focus on a spin ferromagnetic state of the model and study a collective behavior of orbital angular momentum. Orbital order in the model occurs in a nontrivial way—it is stabilized exclusively by quantum effects through the order-from-disorder mechanism. Several energe...
متن کاملEvidence for the Absence of Gluon Orbital Angular Momentum in the Nucleon
The Sivers mechanism for the single-spin asymmetry in unpolarized lepton scattering from a transversely polarized nucleon is driven by the orbital angular momentum carried by its quark and gluon constituents, combined with QCD final-state interactions. Both quark and gluon mechanisms can generate such a single-spin asymmetry, though only the quark mechanism can explain the small single-spin asy...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
عنوان ژورنال:
- Optics express
دوره 19 27 شماره
صفحات -
تاریخ انتشار 2011