Interaction of photonic wheel with cluster of nanoparticles

One of the most intriguing features of structured vector light its optical angular momentum (AM). For a long time it was known that light possesses longitudinal AM which appears due to spin of polarization or phase of the beam. Such beams are known to have screw-like structures in the wavefront and are useful in many areas such as optical trapping, photonics, plasmonics and other. As the interest in AM-related various experimentations and theoretical considerations steadily grows, it was demonstrated that light can also have a transversely orientated AM. This kind of AM state can appear in evanescent waves, structured or focused fields [1] . A propagating field with transverse AM is called a photonic ‘wheel’ [2] . The name of the beam is due to electric field rotation in longitudinal plane to its propagation which is similar to a spinning wheel of riding bicycle.