Related Experiment Video
Updated: Feb 10, 2026

A Photonic System for Generating Unconditional Polarization-Entangled Photons Based on Multiple Quantum Interference
Published on: September 5, 2019
Experimental entangled photon pair generation using crystals with parallel optical axes
Abstract:
We present an optical design where polarization-entangled photon pairs are generated within two β-Barium Borate crystals whose optical axes are parallel. This design increases the spatial mode overlap of the emitted photon pairs enhancing single mode collection without the need for additional spatial walk-off compensators. The observed photon pair rate is at least 65 000 pairs/s/mW with a quantum state fidelity of 99.53 ± 0.22% when pumped with an elliptical spatial profile.
Related Concept Videos
DNA Base Pairing
Ionic Crystal Structures
Most monatomic ions behave as charged spheres, and their attraction for ions of opposite charge is the same in every direction. Consequently, stable structures for ionic compounds result (1) when ions of one charge are surrounded by as many ions as possible of the opposite...
Moments of Inertia for an Area about Inclined Axes
Parallel Processing
Parallel Resonance
Angular Momentum and Principle Axes of Inertia
To put this equation into simpler terms, it can be reconfigured using rectangular coordinates. This involves choosing an alternative set of XYZ axes that are arbitrarily inclined with respect to the reference frame. The process of deriving the rectangular...

