Related Experiment Video
Updated: Jun 4, 2026
11:08
Fabrication And Characterization Of Photonic Crystal Slow Light Waveguides And Cavities
Published on: November 30, 2012
The creation and annihilation of optical vortices using cascade conical diffraction
D P O'Dwyer1, C F Phelan, Y P Rakovich
1School of Physics, Trinity College Dublin, Dublin 2, Ireland.
Optics Express
|March 4, 2011
Summary
Internal conical diffraction generates Bessel-like beams with optical vortices. Cascade conical refraction further manipulates these vortices, enabling all-optical control over optical vortex generation and annihilation based on light polarization.
Area of Science:
- Optics and Photonics
- Quantum Optics
- Condensed Matter Physics
Background:
- Bessel beams are non-diffracting beams with unique properties.
- Optical vortices carry orbital angular momentum.
- Conical diffraction in biaxial crystals leads to complex beam structures.
Purpose of the Study:
- To investigate the generation and manipulation of optical vortices using internal conical diffraction.
- To explore the process of cascade conical refraction for vortex control.
- To establish an all-optical method for optical vortex generation and annihilation.
Main Methods:
- Utilizing internal conical diffraction of a circularly polarized Gaussian beam.
- Propagating the resulting first-order beam through a second biaxial crystal (cascade conical refraction).
- Analyzing the polarization and vortex charge of the generated beams.
Main Results:
- Internal conical diffraction produces a superposition of zero- and first-order Bessel-like beams.
- The first-order beam from right-circularly polarized light carries an optical vortex of charge -1.
- Cascade conical refraction generates superpositions of fields with vortex charges 0 and -1 or 0 and -2.
Conclusions:
- Spin-to-orbital angular momentum conversion is demonstrated.
- A novel all-optical method for generating and annihilating optical vortices is presented.
- The control is solely dependent on incident polarization and vortex handedness.
Related Concept Videos
02:18Interference and Diffraction
Interference is a characteristic phenomenon exhibited by waves. When two electromagnetic waves interact with their peaks and troughs coinciding, a resulting wave with enhanced amplitude is produced. This is known as constructive interference. In this case, the two waves interacting are in phase with each other.
01:26Phase Contrast and Differential Interference Contrast Microscopy
Phase-Contrast Microscopes
In-phase-contrast microscopes, interference between light directly passing through a cell and light refracted by cellular components is used to create high-contrast, high-resolution images without staining. It is the oldest and simplest type of microscope that creates an image by altering the wavelengths of light rays passing through the specimen. Altered wavelength paths are created using an annular stop in the condenser. The annular stop produces a hollow cone of...
In-phase-contrast microscopes, interference between light directly passing through a cell and light refracted by cellular components is used to create high-contrast, high-resolution images without staining. It is the oldest and simplest type of microscope that creates an image by altering the wavelengths of light rays passing through the specimen. Altered wavelength paths are created using an annular stop in the condenser. The annular stop produces a hollow cone of...
01:28Standing Waves in a Cavity
A household microwave and lasers are examples of standing electromagnetic waves in a cavity. When two conducting metal plates are placed parallel at the nodal planes, it creates a cavity where standing waves are formed. The cavity between the two planes is analogous to a stretched string held at the points x = 0 and x = L. Here, the distance 'L' between the two planes must be an integer multiple of half of the wavelength. The wavelengths that satisfy this condition are given by: