Institute of Physics

An analysis is made of the interaction of lasing in two coupled ring resonators with a shared holographic amplifier made of a photorefractive crystal. Derivation is given of relationships between intracavity losses when lasing occurs simultaneously in two resonators or when it takes place in each of them separately. Competition between lasing waves, important in associative optical memory applications, is discussed. Bibtex entry for this abstract Preferred format for this abstract (see Preferences) Find Similar Abstracts: Use: Authors Title Abstract Text Return: Query Results Return items starting with number Query Form Database: Astronomy Physics arXiv e-prints

Currently, optical vortices (OVs), ie, areas of circu-lar motion of energy flow in an electromagnetic wave, are being actively studied in optics. Optical vortices can be divided into longitudinal OVs, where the axis of cir-cular motion coincides with the direction of wave prop-agation ...

Two forms of the transverse energy circulation within plane-polarized paraxial light beams are specified: one inherent in wave-front singularities (optical vortices) and the other peculiar to astigmatism and asymmetry of beams with a smooth wave front. As quantitative measures of these energy flow components, the concepts of vortex and asymmetry parts of a beam's orbital angular momentum are introduced and their definitions are proposed on the basis of beam intensity moments. The properties and physical meaning of these concepts are analyzed, and their use for the study of transformations of optical vortices is demonstrated.

Spatial characteristics of the optical-vortex (OV) beams created during the Gaussian beam diffraction by a grating with groove bifurcation are analyzed theoretically and numerically. In contrast to previous works, condition of small-angle diffraction is no longer required and the diffracted beam can be strongly deformed. This causes the intensity profile rotation and the high-order OV decomposition into a set of secondary single-charged OVs. These effects are studied quantitatively and confronted with similar properties of a Laguerre–Gaussian beam that undergoes astigmatic telescopic transformation. In contrast to the latter case, the secondary OVs do not lie on a single straight line within the beam cross section, and morphology parameters of the individual secondary OVs carried by the same beam are, in general, different. Conditions for maximum relative separation of the secondary OVs with respect to the beam transverse size are specified. The results can be used for practical generation of OV beams and OV arrays with prescribed properties.

Superpositions of coaxial Laguerre-Gaussian modes with common waists and the same Gaussian envelopes are known to form beams whose transverse structures experience the self-similar transformation during free beam propagation: the beam shape remains the same except for the divergence and rotation around the propagation axis. We show that under certain conditions this transformation can be represented as if every point of the beam cross section performs a centrifugal straight-line fly off.

In a \mathcal Q-switched YAG:Nd3+ laser utilizing a three-mirror resonator a reproducible structure of regular fluctuations was obtained with a period corresponding to the reciprocal of the width of the lasing spectrum. When the optical lengths of the partial resonators were not submultiples of the total length, random intensity fluctuations over the entire duration of the giant lasing pulse were observed. Bibtex entry for this abstract Preferred format for this abstract (see Preferences) Find Similar Abstracts: Use: Authors Title Abstract Text Return: Query Results Return items starting with number Query Form Database: Astronomy Physics arXiv e-prints

A structure of wavefront edge dislocations and associated “transversal” optical vortices in an interference field of two two-dimensional Gaussian beams is analyzed. It was shown that the optical vortex rotation is directed toward the area of higher phase velocity in the interference field (the origin of the phase velocity variation is due to the Gouy effect). The conditions for the