Creation of optical speckle by randomizing a vortex-lattice

Area of Science:

• Optics and Photonics
• Quantum Optics
• Laser Physics

Background:

• Speckle patterns are crucial in various optical applications.
• Understanding vortex beam interactions is key to controlling light.
• Previous research has not fully elucidated the conditions for speckle formation using multiple vortices.

Purpose of the Study:

• To determine the optimal number and configuration of optical vortices in a carrier beam for speckle pattern generation.
• To investigate the influence of vortex initial distribution and topological charges on pattern formation.
• To characterize the statistical properties of speckle patterns and identify conditions for well-developed speckle.

Main Methods:

• Utilizing a spatial light modulator to imprint vortex arrays onto a Gaussian beam.
• Propagating the beam in free space and focusing to induce vortex interaction.
• Analyzing the optical field after propagation to a specific transverse plane.
• Complementing experimental findings with comprehensive numerical simulations.

Main Results:

• Identified the critical number and initial distribution of vortices for speckle formation.
• Demonstrated control over ordered and disordered speckle patterns by adjusting parameters.
• Characterized statistical properties of disordered patterns and determined conditions for well-developed speckle.
• Observed vortex pair creation and annihilation influenced by initial conditions.

Conclusions:

• The number, distribution, and topological charge of embedded vortices are critical for generating speckle patterns.
• Experimental and numerical findings provide a framework for controlling speckle formation.
• This research offers insights into vortex dynamics and their role in complex optical field generation.