All articles starting with P
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Photon upconversion
Photon upconversion is the process of combining two or more low-energy photons into one higher-energy photon of shorter wavelength, studied for use in photovoltaics, photocatalysis, and biological imaging.
Photon upconversion in lanthanide-doped nanocrystals
Photon upconversion in lanthanide-doped nanocrystals is a process where lanthanide ions in a nanocrystal absorb two or more low-energy near-infrared photons and emit one higher-energy photon.
Photon-assisted tunnelling
Photon-assisted tunnelling is quantum tunnelling in which an electron absorbs or emits energy quanta from an oscillating electromagnetic field, first observed in superconducting junctions in the 1960s.
Photon-counting communication
Photon-counting communication is a form of optical communication in which the receiver detects and registers individual photons, used in deep-space laser links and satellite quantum key distribution.
Photon-counting computed tomography
Photon-counting computed tomography (PCCT) is a CT technique whose detectors count individual X-ray photons, sharpening resolution and separating materials; the first clinical scanner, the Siemens NAEOTOM Alpha, was FDA-cleared in 2021.
Photon-number-resolving detection
Photon-number-resolving detection measures the number of photons in each optical pulse rather than just their presence, and is required for linear optical quantum computing, quantum key distribution, and light source characterization.
Photoneo
Photoneo is a Slovak developer of 3D machine vision sensors and software for industrial robotics, founded in Bratislava in 2013 and acquired by Zebra Technologies in 2025.
Photonic Aharonov–Bohm effect
The photonic Aharonov–Bohm effect is the light-wave analog of the Aharonov–Bohm effect, where photons acquire a nonreciprocal phase from engineered gauge potentials, first demonstrated in 2013.
Photonic band gap
A photonic band gap is a range of frequencies at which light cannot propagate in a photonic crystal, proposed independently by Eli Yablonovitch and Sajeev John in 1987.
Photonic bandgap fiber
A photonic bandgap fiber is an optical fiber that confines light by a photonic bandgap effect rather than total internal reflection, allowing a hollow air core first demonstrated in 1999.
Photonic bound states (Rydberg polaritons)
Photonic bound states, formed with Rydberg polaritons in cold atomic gases, are packets of two or more photons that travel together because they attract one another, first observed in 2013.
Photonic chip-based squeezed-light quantum computing
Photonic chip-based squeezed-light quantum computing generates and measures squeezed states of light on integrated photonic chips, the continuous-variable architecture behind Xanadu's cloud-accessible Borealis and Aurora systems.
Photonic crystal
A photonic crystal, also known as a photonic lattice, is a material whose dielectric constant varies periodically, creating photonic band gaps that forbid light propagation, invented by Yablonovitch and John in 1987.
Photonic crystal cavity
A photonic crystal cavity is an optical resonator made by introducing a defect into a periodic dielectric lattice, trapping light in volumes near the diffraction limit.
Photonic crystal surface-emitting laser
A photonic crystal surface-emitting laser (PCSEL) is a semiconductor diode laser, first proposed in 1999, whose embedded 2D photonic crystal cavity enables high-power, single-mode, circular-beam surface emission.
Photonic crystal waveguide
A photonic crystal waveguide (PCW) is an optical waveguide formed by a line defect in a photonic crystal, guiding light near a band gap where it can be slowed.
Photonic curing
Photonic curing, also known as photonic sintering or flash lamp annealing, heats thin films with millisecond light pulses, sintering printed metal inks on plastic and paper without damage.
Photonic doping
Photonic doping is a photonics technique in which subwavelength dielectric particles inserted anywhere in an epsilon-near-zero medium tune its effective magnetic permeability, introduced in a 2017 Science paper.
Photonic Floquet topological insulators
A photonic Floquet topological insulator is an optical structure whose periodic driving, in time or along propagation, produces topologically protected one-way edge states of light, first realized in 2013.
Photonic integrated circuit
A photonic integrated circuit (PIC) is a chip on which optical components such as waveguides, lasers, and photodetectors are fabricated together to process light signals.
Photonic inverse design
Photonic inverse design is an optical device design methodology in which the desired functionality is specified first and an optimization algorithm searches for a suitable structure.
Photonic Landau levels
Photonic Landau levels are discrete, highly degenerate bands formed when engineered photonic systems make uncharged light behave as if in a magnetic field, first realized in 2013.
Photonic metamaterial
A photonic metamaterial is an artificial optical material built from subwavelength metallo-dielectric structures, engineered to show negative refractive indices, artificial magnetism, perfect lenses, and cloaking.
Photonic moiré metasurfaces
Photonic moiré metasurfaces are pairs of overlapped artificial optical lattices, often mutually twisted, whose moiré superlattice continuously tunes how light propagates, localizes, and radiates without refabrication.
Photonic Mott insulator
A photonic Mott insulator is a many-body state of light in which photons confined to a lattice of coupled cavities localize one per site, forming an incompressible phase.
Photonic neural network
A photonic neural network is a neural network built from optical components like Mach-Zehnder interferometers, so light rather than electronics performs the linear operations of machine learning.
Photonic quantum computing
Photonic quantum computing performs quantum computation with photons as qubits, usually at room temperature, its main challenge being that photons barely interact, making two-qubit gates probabilistic.
Photonic quantum Hall effect
The photonic quantum Hall effect is the light analog of the electronic quantum Hall effect, proposed in 2008, producing unidirectional edge states of light that resist backscattering.
Photonic quantum spin Hall effect
The photonic quantum spin Hall effect is the optical analog of the electronic quantum spin Hall effect, in which light flows along a photonic crystal's boundaries as helical edge states.
Photonic skyrmions
Photonic skyrmions, also called optical skyrmions, are particle-like topological textures in which light's polarization wraps around a sphere, first observed in 2018 and studied for robust optical encoding.