Diffraction characteristics of optical elements designed as phase layers with cosine-profiled periodicity in azimuthal direction

TL;DR

This paper investigates the diffraction patterns of two azimuthally periodic phase optical elements under Gaussian laser illumination, revealing how cosine-profiled phase modulations affect their vortex characteristics.

Contribution

It introduces two types of azimuthally periodic phase elements and analyzes how their cosine-profiled phase changes influence diffraction patterns and vortex properties.

Findings

Cosine-profiled phase modulations produce azimuthal cosine patterns in diffraction.

These modulations destroy vortex characteristics in the diffraction fields.

The second element combines phase layers with a phase axicon, affecting diffraction behavior.

Abstract

The article concerns an investigation of the Fresnel diffraction characteristics of two types of phase optical elements, under Gaussian laser beam illumination. Both elements provide an azimuthal periodicity of the phase retardation. The first element possess azimuthal cosine-profiled phase changes deposited on a plane base. The second element is a combination of the first element and a thin phase axicon. The cosine profile of the phase retardation, of both diffractive elements, produces an azimuthal cosine-profiled modulation on their diffractograms. It destroys the vortex characteristics of their diffraction fields.