15 research outputs found
Off-axis vortex beam propagation through classical optical system in terms of Kummer confluent hypergeometric function
The analytical solution for the propagation of the laser beam with optical
vortex through the system of lenses is presented. The optical vortex is
introduced into the laser beam (described as Gaussian beam) by spiral phase
plate. The solution is general as it holds for the optical vortex of any
integer topological charge, the off-axis position of the spiral phase plate and
any number of lenses. Some intriguing conclusions are discussed. The higher
order vortices are unstable and split under small phase or amplitude
disturbance. Nevertheless, we have shown that off-axis higher order vortices
are stable during the propagation through the set of lenses described in
paraxial approximation, which is untypical behavior. The vortex trajectory
registered at image plane due to spiral phase plate shift behaves like a rigid
body. We have introduced a new factor which in our beam plays the same role as
Gouy phase in pure Gaussian beam.Comment: 28 pages, 8 figure
Polygonal micro-whirlpools induced in ferrofluids
We report on the observation of the polygonal whirlpools in the thin layer of
ferrofluid under illumination with a laser beam carrying optical vortex and in
the presence of a vertical magnetic field. This kind of structures have
attracted attention after discovering a hexagonal storm in Saturns atmosphere.
Our polygonal whirlpools were created in a closed system (no free surfaces) in
micro scale (whirlpool diameter less than 20 micrometers) by the use of
holographic optical tweezers. The polygonal shape was changed by varying the
magnetic field strength or value of the optical vortex topological charge
Interferometry with Vortices
Interference of optical beams with optical vortices is often encountered in singular optics. Since interferometry makes the phase observable by intensity measurement, it brings out a host of applications and helps to understand the optical vortex. In this article we present an optical vortex interferometer that can be used in optical testing and has the potential to increase the accuracy of measurements. In an optical vortex interferometer (OVI), a lattice of vortices is formed, and the movement of the cores of these vortices is tracked when one of the interfering beams is deformed. Instead of multiple vortices in an OVI, an isolated single vortex also finds applications in optical testing. Finally, singularity in scalar and vector fields is presented, and the relation between them is illustrated by the superposition of these beams
LBSA: A GUI-based Matlab software for the advanced laser beam shaping with spatial light modulators
We present LBSA — a complex laser beam shaping application that integrates the design and control features into a single graphical user interface app. This approach makes the advanced beam shaping operations accessible even for non-technical users. The control component automatically detects both the reflective spatial light modulator and an external camera, while the design one, offers built-in phase shaping functions. These enable complex beam shaping from a single standalone app. In this work, we go through each of the LBSA components, describe their features, and provide a usage example based on experimental results