The vortex lattice can be practically used in metrology. The Optical Vortex Interferometer (OVI) is an useful tool to
generate a regular lattice of optical vortices. Unfortunately, there are still many problems that have to be solved before an
OVI-based device can go into production. In this paper experimental results of using another type of OVI, OVI with one
focused beam, are presented. The results of measuring small displacements of reflecting areas are also shown.
In this paper authors present the method for measurement of micro displacements along optical axis of the reflective
object. Three separate focused beams are used in those measurements. Those three plane waves are reflected by
examined object surface and their interference tends to create regular lattice of the optical vortices. In this paper authors
present test results of sensitivity of an actual measurement system.
In recent years a lot of effort was put into testing and improving the idea of a three beam interferometer known as
Optical Vortices Interferometer (OVI). Devices based on the idea of an OVI allow measuring small rotation angles and
small shifts with a superb resolution<sup>1,2</sup>. Unfortunately there are still many problems that have to be solved before an OVIbased
device can go into production. In this paper there are presented theoretical calculations and experimental results of
using another type of OVI - OVI with focused beam, for measuring small displacements and small rotation angles of
In an interferometer based on optical vortices there are generated regular net of phase singularities. There are
two kinds of optical vortex named positive and negative. The sign of the vortex is often named a topological charge of
the optical vortex because its existence is related to the characteristic of the geometric wavefront. The ability to
determine the sign of the optical vortices in the experimental measurements may be used to reconstruct the wavefront. In
this paper authors present the experimental method to determine the sign of the optical vortices.
The optical vortices were intensively studied during last decade. In the literature there are papers presenting application of the optical vortices. The regular net of optical vortices generated by the three plane waves interference allows for the new kind of the interferometer - the Optical Vortex Interferometer (OVI). The precision of the OVI depends on the localization accuracy and the phase reconstruction. The localization methods give errors if we use beamsplitters with coatings changing the polarization state of the light. There are six beamsplitters used in this interferometer. In the setup we used non-polarizing coatings. We observed pleochroism effect, which occurs in these coatings. It is the cause of errors in the localization of optical vortices. In this paper we study the effect of pleochroism and we show the way to avoid errors in the localization of optical vortices in the OVI.
In this paper the new method of parallel glass plat test is presented. In the method an Optical Vortex Interferometer (OVI) is used. The OVI generate the regular net of optical vortices by interference of three plane waves. One wave is deformed after crossing measured parallel glass plate. The deformation of the wave-front is measurable because the deformation of vortex net structure arises from the wave-front deformation. The record of the vortex points' positions before and after parallel glass plate insertion in the optical arrangement is essential. Shown in this paper the analysis vortex points positions change gives high precision information about real shape of the parallel glass plate.
A regular net of optical vortices generated by three plane waves interference allows for a new kind of interferometer -
Optical Vortex Interferometer. The precision of that kind of interferometer depends on a localization accuracy and phase
reconstruction. One problem is the unique phase reconstruction. Interference of three waves can generate two identical
interferograms with opposite topological charge of vortices, so information from three waves interferogram is not
enough to the unique phase reconstruction. First method of topological charge determination requires one interferogram
of two waves analyzed in an experiment and knowledge about a direction of laser beams. Second method is based on
analysing interferogram with the fourth wave added.
The regular net of optical vortices can be generated by three plane wave interference. Such regular vortices are used in a new kind of interferometry—optical vortex interferometry. In this work, the experimental method for topological charge determination of optical vortices in a regular net is presented. This allows for unique phase reconstruction in optical vortex interferometry and solves what is known in interferometry as the phase unwrapping problem.