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Polarizable continuum model
The polarizable continuum model (PCM) is a computational chemistry method representing solvent as a polarizable dielectric around a solute in a molecular-shaped cavity, first reported in 1981.
Polarizable force field
A polarizable force field is a molecular mechanics model whose atomic charges respond explicitly to their environment, unlike conventional fixed-charge models, with induced dipole, Drude, and fluctuating charge approaches.
Polarization (physics)
Polarization, also called light polarization, is a property of transverse waves describing the direction in which the electric field oscillates, with linear, circular, and elliptical states.
Polarization (waves)
Polarization is a property of transverse waves in which the oscillations have a definite direction relative to propagation; for light, it is the electric field's direction.
Polarization analysis (seismology)
Polarization analysis in seismology characterizes the direction and shape of ground particle motion recorded by three-component seismic stations, supporting event detection, direction finding, and filtering.
Polarization analysis with Stokes parameters
Polarization analysis with Stokes parameters determines the polarization state of light from four measurable parameters, I, Q, U, and V, introduced by George Gabriel Stokes in 1852.
Polarization beam splitter
A polarization beam splitter (PBS) is a widely used optical device that separates light's two polarizations into different beams, used in optical communications, imaging, interferometers, and quantum optics.
Polarization density
Polarization density, also called electric polarization, is the vector field P measuring electric dipole moment per unit volume of a dielectric in an applied field.
Polarization grating
A polarization grating is a diffractive optical element that periodically modulates the polarization of light, so diffraction direction depends on polarization; applications include lidar beam steering and snapshot polarimetry.
Polarization holography
Polarization holography is a holographic recording technique that stores the amplitude, phase, and polarization of light simultaneously in a photoanisotropic material, enabling polarization multiplexing and vector beam generation.
Polarization imaging
Polarization imaging is an optical technique that records the polarization state of light interacting with a sample, pixel by pixel, revealing properties like birefringence and anisotropy.
Polarization microscopy
Polarization microscopy is an optical technique that passes light through polarizing filters to reveal birefringent specimens, measuring retardation and axis orientation; it is used in petrography, mineralogy, and biology.
Polarization mode dispersion
Polarization mode dispersion is the mean differential group delay between the two orthogonal polarization modes of single-mode optical fiber, significant at bit rates of 40 Gbit/s and above.
Polarization modulation infrared reflection–absorption spectroscopy
Polarization modulation infrared reflection–absorption spectroscopy (PM-IRRAS) is a surface-sensitive infrared technique that measures vibrational spectra of molecules adsorbed on metal substrates, canceling atmospheric background by rapidly switching between p- and s-polarized light.
Polarization spectroscopy
Polarization spectroscopy measures how matter changes the polarization state of light, using a pump beam to induce anisotropy and a probe beam to detect it.
Polarization-maintaining optical fiber
Polarization-maintaining optical fiber (PM fiber), also called polarization-preserving fiber, is a specialty single-mode fiber whose strong built-in birefringence preserves light's polarization; applications include fiber-optic gyroscopes, interferometers, and fiber lasers.
Polarized filtering
Polarized filtering is an optical technique using polarizers to transmit one polarization state and reject the orthogonal component, applied in fluorescence microscopy, Raman spectroscopy, and polarimetric imaging.
Polarized ion source
A polarized ion source is an accelerator device that produces beams of protons, deuterons, or helium-3 whose nuclear spins are aligned in a chosen direction rather than random.
Polarized light microscopy
Polarized light microscopy (PLM) is an optical technique that illuminates samples with polarized light between crossed polarizers, revealing birefringence in minerals, fibers, and living cells.
Polarized neutron reflectometry
Polarized neutron reflectometry, or polarized neutron reflectivity, is a neutron scattering technique that measures spin-dependent reflectivity to map magnetization depth profiles in thin films and buried layers.
Polarizer
A polarizer, or polarizer, is an optical filter that transmits light vibrating in one direction and blocks the rest, used in sunglasses, camera filters, and LCDs.
Polarizing filter (photography)
A polarizing filter is a camera lens filter that suppresses reflections on water and glass, cuts haze, and increases color saturation, effects that cannot be replicated in editing.
Polarizing microscope
A polarizing microscope, also called a petrographic or geology microscope, is a light microscope using polarized light, chiefly for identifying rocks and minerals in thin section.
Polarography
Polarography is an electroanalytical technique using a dropping mercury electrode, introduced by Jaroslav Heyrovský in Prague in 1922 and honored with the 1959 Nobel Prize in Chemistry.
Polaron
A polaron is a quasiparticle made of an electron or hole plus the surrounding crystal lattice distortion it induces, a concept Lev Landau introduced in 1933.
Pole star
A pole star is a star that lies near a celestial pole and stays nearly fixed as the sky revolves; Polaris is the current northern one.
Poleta Formation
The Poleta Formation is an Early Cambrian sedimentary unit of limestone and siltstone exposed in the White and Inyo Mountains of California and western Nevada, named by C. A. Nelson in 1962.
Polignac's conjecture
Polignac's conjecture, stated by Alphonse de Polignac in 1849, claims every even number occurs infinitely often as a difference between consecutive primes; its gap-2 case is the twin prime conjecture.
Polish Hydrobiological Society
The Polish Hydrobiological Society (Polskie Towarzystwo Hydrobiologiczne, PTH) is a Polish scientific association founded in 1959 that supports research in hydrobiology, the study of aquatic organisms.
Polish notation
Polish notation, also called prefix notation or Łukasiewicz notation, is a mathematical notation, invented by Jan Łukasiewicz in 1924, in which operators precede their operands.