Visualization of the birth of an optical vortex using diffraction from a triangular aperture

Area of Science:

• Optics and Photonics
• Quantum Optics
• Laser Physics

Background:

• Optical vortices are crucial in various applications.
• Determining the azimuthal index (topological charge) of optical vortex beams is a significant challenge.
• Previous studies have not fully explored the diffraction of optical vortices from apertures with complex geometries.

Purpose of the Study:

• To investigate the diffraction of optical vortex beams from a triangular aperture.
• To demonstrate the influence of the azimuthal index and Gouy phase on diffraction patterns.
• To explore the behavior of optical vortices with non-integer azimuthal indices.

Main Methods:

• Simulating and analyzing the far-field diffraction patterns of optical vortex beams incident on a triangular aperture.
• Utilizing both monochromatic and broadband light fields.
• Observing diffraction patterns for varying azimuthal indices, including non-integer values.

Main Results:

• The diffraction pattern's form is dependent on both the magnitude and sign of the azimuthal index (ℓ).
• This dependency holds true for both monochromatic and broadband light.
• The Gouy phase component of the incident beam critically influences the diffraction behavior.
• The birth and evolution of vortices at half-integer azimuthal indices were observed and inferred.

Conclusions:

• A triangular aperture is a versatile tool for studying optical vortices.
• The diffraction patterns provide insights into the complex vortex structure and evolution.
• The findings contribute to a deeper understanding of optical vortex properties and their manipulation.