Interferometry with Vortices

Abstract

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.

Compton Scattering of a Vortex Light Beam

“…The ratio of linear to orbital light momenta forms, given in equation (2), can be interpreted in a certain geometrical sense. Light orbital angular momentum is directly proportional to linear momentum in such a way L depends on the orientation of P along of the propagation axis.…”

“…It is easy to use equations (2) and (7) to show that orbital angular momentum vanishes when the axial linear momentum is perfectly aligned with the propagation axis (φ = 0). Note that singularity point exists at the center of a vortex beam.…”

“…Vortex Light beam does have phase singular corresponds to a wave with helical phase structure at the center of the beam the intensity vanishes due to singularity [2]. Orbital angular momentum, of a single photon, is quantized by an integer number called the topological charge of the vortex beam [3].…”

Singularities in cylindrical vector beams

“…The topology is such that all the wavefronts which are disconnected and separated by distance k with each other in an otherwise non-singular beam, become connected thereby forming a single wavefront filling the entire space. The optical vortices can be characterized by various interferometry techniques [4][5][6][7]. In two beam interferometry, fork-type fringes (characteristic of phase singularity) appear at the singular region.…”

Partially coherent stable and spiral beams

“…Coherent stable beams (cSTBs), such as HG, LG, HLG, and IG modes, and coherent spiral beams (cSPBs) [16][17][18][19][20] are widely used nowadays for particle manipulation [21,22], resolution improvement in microscopy [23][24][25][26], free-space communication [27], atmosphere monitoring [28,29], etc. Moreover, it has been shown that as well as the Bessel beams, the cSTBs (and similarly, the cSPBs) are able to reconstruct their forms after propagation through small obstacles.…”