Manipulation of the orbital angular momentum of soft x-ray beams by consecutive diffractive optics

TL;DR

This paper demonstrates the control and manipulation of orbital angular momentum in soft x-ray beams using consecutive diffractive optics, enabling new experimental techniques and beam characterization methods.

Contribution

It introduces a method for manipulating OAM in soft x-ray beams with consecutive diffractive optics, decoupling OAM from spin angular momentum.

Findings

OAM addition observed with consecutive fork gratings

OAM can be manipulated independently of SAM in soft x-ray beams

Potential for direct OAM measurement without phase-sensitive techniques

Abstract

Production and manipulation of orbital angular momentum (OAM) of coherent soft x-ray beams is demonstrated utilizing consecutive diffractive optics. OAM addition is observed upon passing the beam through consecutive fork gratings. The OAM of the beam was found to be decoupled from its spin angular momentum (SAM). Practical implementation of angular momentum control by consecutive devices in the x-ray regime opens new experimental opportunities, such as direct measurement of OAM beams without resorting to phase sensitive techniques, including holography. OAM analyzers utilizing fork gratings can be used to characterize the beams produced by synchrotron and free electron lasers sources; they can also be used in scattering experiments.