Abstract
An imperfect propagation environment or optical system would introduce wavefront aberrations to vortex beams. The phase aberrations and orbital angular momentum in a vortex beam are proved to be mutually restrictive in parameter measurement. Aberrations make traditional topological charge (TC) probing methods ineffective while the phase singularity makes phase retrieval difficult due to the aliasing between the wrapped phase jump and the vortex phase jump. An interactive probing method is proposed to make measurements of the aberrated phase and orbital angular momentum in a vortex beam assist rather than hinder each other. The phase unwrapping is liberated from the phase singularity by an annular shearing interference technique while the TC value is determined by a Moiré technique immune to aberrations. Simulation and experimental results proving the method effective are presented. It is of great significance to judge the characteristics of vortex beams passing through non-ideal environments and optical systems.
Funder
National Natural Science Foundation of China
Open Funding of Magnetic Confinement Fusion Laboratory of Anhui Province
Subject
Atomic and Molecular Physics, and Optics,Electronic, Optical and Magnetic Materials