Related papers: Beam quality $M^2(\psi)$ factor, spot rotation ang…
Beam quality is a fundamental aspect for evaluating the performance of laser sources. $M^2$-measurements serve as the gold standard for beam quality assessment since the 1990s. The measured $M^2$-parameter indicates similarity to the pure…
The propagation and divergence properties of beams carrying orbital angular momentum (OAM) play a crucial role in many applications. Here we present a general study on the divergence of optical beams with OAM. We show that the mean absolute…
We consider the propagation of slow light with an orbital angular momentum (OAM) in a moving atomic medium. We have derived a general equation of motion and applied it in analysing propagation of slow light with an OAM in a rotating medium,…
Laser brightness is crucial in many optical processes, and is optimised by high power, high beam quality (low $M^2$) beams. Here we show how to improve the laser beam quality factor (reducing the $M^2$) of arbitrary structured light fields…
The optical vortices carrying orbital angular momentum (OAM) are commonly generated by modulating the available conventional light beam. This article shows that a micro-laser operates at the exceptional point (EP) of the non-Hermitian…
Frequency analysis of long-term ultra-precise photometry can lead to precise values of rotation frequencies of rotating stars with ``hump and spike'' features in their periodograms. Using these features, we computed the rotation frequencies…
Motivated by the necessity of a high-quality stray light control in the detection of the gravitational waves in space, the spot size of a flat top beam generated by the clipping of the Gaussian beam (GB) is studied. By adopting the mode…
We show, both theoretically and experimentally, that the propagation of optical vortices in free space can be analysed by using the width ($w(z)$) of the host Gaussian beam and the inner and outer radii of the vortex beam at the source…
From the standard TEM00 Gaussian beam profile equations, we have derived the equations for beam waist at lens focus as a function of variable spot size. In this process, we obtained two equations for beam waist and the validity of these…
We describe methods to measure simultaneously the orientation angle $\psi$ and pattern speed $\Omega$ from single snapshots of simulated barred galaxies. Unlike previous attempts, our approach is unbiased, precise, and consistent in the…
With increasing interest in using orbital angular momentum (OAM) modes in high-power laser systems, accurate mathematical descriptions of the high-intensity modes at focus are required for realistic modelling. In this work, we derive…
In radiation beam-profile measurements, an accurate positioning of the detector with high position resolution is essential. For this purpose, we built a scanning device capable of moving a detector in three dimensions using mainly parts…
We presented a new method for measuring the squares of the amplitudes and phases of partial vortex-beams in a complex beam array in real time. The method is based on measuring the high-order intensity moments and analyzing the solutions of…
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…
The expression for the total angular momentum carried by a laser optical vortex beam, splits, in the paraxial approximation, into two terms which seem to represent orbital and spin angular momentum respectively. There are, however, two very…
One of the most widely used techniques for measuring the orbital angular momentum components of a light beam is to flatten the spiral phase front of a mode, in order to couple it to a single-mode optical fiber. This method, however, suffers…
We present a real-time method to determine the beam propagation ratio M2 of laser beams. The all-optical measurement of modal amplitudes yields M2 parameters conform to the ISO standard method. The experimental technique is simple and fast,…
The orbital angular momentum (OAM) of light and matter waves is a parameter that is getting increasingly more attention over the past couple of years. Beams with a well defined OAM, the so-called vortex beams, are applied already in e.g.…
One of the challenges for every optical system is preserving the quality of the used beam, which may be significantly reduced, due to the low condition of used optical elements or their misalignment. There are plenty of methods focused on…
We explore a subtle and fundamental nature of spin-orbit interaction (SOI) in a general paraxial beam-field by mathematically characterizing the orbital angular momentum (OAM) flux densities of the spin-polarized component fields via…