Photon Pair Generation
Photon Pair Generation - Related Videos
00:07
A Photonic System for Generating Unconditional Polarization-Entangled Photons Based on Multiple Quantum Interference
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Cited by 1 •
2019
We describe an optical system for the generation of unconditional polarization-entangled photons based on multiple quantum interference effects with a detection scheme to estimate the experimental fidelity of generated entangled photons.
02:27
DNA Base Pairing
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2020
Erwin Chargaff’s rules on DNA equivalence paved the way for the discovery of base pairing in DNA. Chargaff’s rules state that in a double-stranded DNA molecule, the amount of adenine (A) is equal to the amount of thymine (T); the amount of guanine (G) is equal to the amount of cytosine (C); and the sum of purines, A and G, is equal to the sum of pyrimidines, C and T (i.e., A+G = C+T). Later work by Watson and Crick revealed that in double-stranded DNA, A always forms two hydrogen bonds...
10:35
Using Microwave and Macroscopic Samples of Dielectric Solids to Study the Photonic Properties of Disordered Photonic Bandgap Materials
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2014
Disordered structures offer new mechanisms for forming photonic bandgaps and unprecedented freedom in functional-defect designs. To circumvent the computational challenges of disordered systems, we construct modular macroscopic samples of the new class of PBG materials and use microwaves to characterize their scale-invariant photonic properties, in an easy and inexpensive manner.
12:19
Measurement of Quantum Interference in a Silicon Ring Resonator Photon Source
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Cited by 2 •
2017
Silicon photonic chips have the potential to realize complex integrated quantum systems. Presented here is a method for preparing and testing a silicon photonic chip for quantum measurements.
04:01
VSEPR Theory and the Effect of Lone Pairs
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2020
Effect of Lone Pairs of Electrons on Molecule Geometry It is important to note that electron-pair geometry around a central atom is not the same thing as its molecular structure. Molecular structure describes the location of the atoms, not the electrons. The geometry that includes all electron pairs is the electron-pair geometry. The electron-pair geometries describe all regions where electrons are located, bonds as well as lone pairs. The structure that includes only the placement of the...
FAQs
Energy and momentum conservation establish the allowed output states, while phase matching determines whether the nonlinear interaction accumulates constructively. These constraints link the photons’ frequencies, propagation directions, and correlations to the pump and material properties. In engineering designs, controlling phase matching is therefore central to directing usable photon pairs toward the collection system.
Spontaneous parametric down-conversion and four-wave mixing rely on different nonlinear processes and device platforms. The former uses a nonlinear crystal, whereas related sources can use waveguides or fibers. That distinction affects how engineers choose materials, geometry, and operating conditions, allowing the source architecture to match requirements for propagation, optical control, and the desired photon correlations.
Pair performance depends on more than the conversion process itself. Engineers adjust material choice, phase matching, pump conditions, and collection optics to increase pair rates while reducing noise. These variables also influence how efficiently the correlated photons are directed and retained for later experiments, so optimization requires balancing generation rates against the quality of the collected optical signal.
A practical design workflow begins by selecting a nonlinear crystal, waveguide, or fiber platform, then establishing suitable pump conditions and phase matching. Engineers next configure collection optics to capture the desired directions and frequencies. Evaluating pair rates, noise, and observed correlations provides feedback for refining the material, operating conditions, and optical configuration.
Measurements can reveal whether the source produces the intended frequencies, directions, and correlations, while pair rates indicate how effectively the process generates usable events. Noise measurements show whether unwanted optical signals compromise the output. Together, these outcomes help engineers compare designs and determine whether a source is suitable for downstream quantum-photonic experiments.
It supplies a foundation for quantum communication, entanglement-based sensing, photonic computing, and experiments testing fundamental properties of light. Engineering decisions about nonlinear materials, phase matching, pump conditions, and collection optics determine how well a source serves these goals. The same design principles connect device development with practical control of correlations and optical performance.