Related Experiment Video
Updated: Jan 11, 2026

A Photonic System for Generating Unconditional Polarization-Entangled Photons Based on Multiple Quantum Interference
Published on: September 5, 2019
Observation of the classical entanglement of twisted partially coherent light in phase space
Abstract:
Recently, a new form of classical entanglement between phase space degrees of freedom in twisted partially coherent beams has been theoretically predicted [Opt. Lett.46, 5958 (2021)10.1364/OL.445258]. Here, we report the first, to our knowledge, experimental observation of such phase-space entanglement (nonseparability) in a twisted Gaussian Schell-model (TGSM) beam via four-dimensional Wigner distribution function measurements, realized through the scanned windowed Fourier transform method. The Wigner distribution measurement enables direct visualization of phase-space nonseparability in the beam. Moreover, we demonstrate that the twist factor of the TGSM beam can be precisely determined from phase-space measurements. Furthermore, the Wigner distribution reveals the nonuniform spatial correlation properties of the TGSM beam and the rotational symmetry of its spatial coherence structure. Our method provides a versatile platform for probing phase-space nonseparability in random light fields.
Related Concept Videos
Space-Time Curvature and the General Theory of Relativity
This has been verified in many experiments. However, space and time are no longer absolute. Two observers moving relative to one another do not agree on the length of objects or the passage of time. The mechanics of objects based on Newton's laws of...
Interference and Diffraction
The Wave Nature of Light
The de Broglie Wavelength
Symmetry in Maxwell's Equations
Plane Electromagnetic Waves II

