Related Experiment Video
Updated: May 23, 2026
07:56
A Photonic System for Generating Unconditional Polarization-Entangled Photons Based on Multiple Quantum Interference
Published on: September 5, 2019
Polarization pattern of vector vortex beams generated by q-plates with different topological charges
Filippo Cardano1, Ebrahim Karimi, Sergei Slussarenko
1Dipartimento di Scienze Fisiche, Università di Napoli Federico II, Napoli, Italy.
Applied Optics
|April 17, 2012
Summary
We explored polarization topology in liquid crystal q-plates. These devices generate vector beams, enabling dynamic switching between radial and azimuthal polarizations for optical applications.
Area of Science:
- Optics and Photonics
- Liquid Crystal Displays
- Vector Beam Generation
Background:
- Vector beams possess complex polarization structures.
- Liquid crystal devices offer tunable optical properties.
- Topological charge in optical elements influences beam characteristics.
Purpose of the Study:
- To investigate the polarization topology of vector beams from q-plates.
- To experimentally characterize polarization structures for various q-plates and input states.
- To demonstrate dynamic generation of cylindrical vector beams using a q=1/2-plate.
Main Methods:
- Experimental measurement of Stokes parameters point-by-point in the transverse plane.
- Utilizing patterned birefringent liquid crystal plates (q-plates).
- Employing a tuned q=1/2-plate for controlled polarization generation.
Main Results:
- Detailed mapping of polarization topological structures for different q-plates.
- Successful generation of radial and azimuthal vector beams.
- Demonstrated dynamic switching between radial and azimuthal polarizations by altering input polarization.
Conclusions:
- Q-plates provide versatile control over vector beam polarization.
- The polarization topology is dependent on q-plate design and input polarization.
- Dynamic control of cylindrical vector beams is achievable with simple input adjustments.
Related Concept Videos
01:29Potential Due to a Polarized Object
A neutral atom consists of a positively charged nucleus surrounded by a negatively charged electron cloud. When placed in an external electric field, the external electric force pulls the electrons and nucleus apart, opposite to the intrinsic attraction between the nucleus and the electrons. The opposing forces balance each other with a slight shift between the center of masses of the nucleus and the electron cloud, resulting in a polarized atom. On the other hand, a few molecules, like water,...
01:16Electric Field of Parallel Conducting Plates
Gauss' law relates the electric flux through a closed surface to the net charge enclosed by that surface. Gauss's law can be applied to find the electric field and the charge enclosed in a region depending on its charge distribution.
Consider a cross-section of a thin, infinite conducting plate having a positive charge. For such a large thin plate, as the thickness of the plate tends to zero, the positive charges lie on the plate's two large faces. Without an external electric field, the...
Consider a cross-section of a thin, infinite conducting plate having a positive charge. For such a large thin plate, as the thickness of the plate tends to zero, the positive charges lie on the plate's two large faces. Without an external electric field, the...
01:27Magnetic Fields
A moving charge or a current creates a magnetic field in the surrounding space, in addition to its electric field. The magnetic field exerts a force on any other moving charge or current that is present in the field. Like an electric field, the magnetic field is also a vector field. At any position, the direction of the magnetic field is defined as the direction in which the north pole of a compass needle points.
A magnetic field is defined by the force that a charged particle experiences...
A magnetic field is defined by the force that a charged particle experiences...
01:31Dielectric Polarization in a Capacitor
The presence of a dielectric medium in a capacitor not only changes the voltage and capacitance but also affects the electric field. In general, dielectrics can be of two types: polar and nonpolar. In a polar dielectric, the positive and negative charges in the molecules are separated by a distance and hence have a permanent dipole moment. In contrast, no such charge separation exists in a nonpolar dielectric, however the nonpolar molecules get polarized in the presence of an external electric...
01:23Magnetic Field due to Moving Charges
A stationary charge creates and interacts with the electric field, while a moving charge creates a magnetic field.
Consider a point charge moving with a constant velocity. Like the electric field, the magnetic field at any point is directly proportional to the magnitude of the charge and inversely proportional to the square of the distance between the source point and the field point. However, unlike the electric field, the magnetic field is always perpendicular to the plane containing the line...
Consider a point charge moving with a constant velocity. Like the electric field, the magnetic field at any point is directly proportional to the magnitude of the charge and inversely proportional to the square of the distance between the source point and the field point. However, unlike the electric field, the magnetic field is always perpendicular to the plane containing the line...
01:30Electric Field of Two Equal and Opposite Charges
Atoms generally contain the same number of positively and negatively charged particles, protons, and electrons. Hence, they are electrically neutral. However, the centers of the positive and negative charges do not always coincide. In such a scenario, the electric field of an atom may not be zero.
A separation of the positive and negative charges can lead to a weak, remnant effect of the positive and negative charges. The expectation is that the more the distance between the positive and...
A separation of the positive and negative charges can lead to a weak, remnant effect of the positive and negative charges. The expectation is that the more the distance between the positive and...