42,772 articles
Optical torque
Optical torque is the twisting mechanical effect produced when light transfers angular momentum to matter. It was first measured mechanically in 1936 and now drives micromachines and single-molecule studies.
Optical transfer function
The optical transfer function (OTF) describes how an optical imaging system, such as a camera or microscope, transfers contrast and phase of spatial detail from object to image.
Optical trapping in liquid crystals
Optical trapping in liquid crystals uses focused laser light, typically optical tweezers, to hold, move, and assemble particles and defects dispersed in a nematic liquid crystal.
Optical tweezer array
An optical tweezer array is a set of focused laser beams that trap individual neutral atoms as qubits, a leading platform for quantum computing and simulation.
Optical tweezer-array atomic clock
An optical tweezer-array atomic clock, or tweezer clock, is an optical atomic clock in which many individually trapped neutral atoms are interrogated together, combining lattice-clock precision with single-atom control.
Optical tweezers
Optical tweezers, also called laser tweezers, are scientific instruments in which a tightly focused laser beam traps a microscopic particle in three dimensions, first demonstrated by Arthur Ashkin in 1986.
Optical vortex
An optical vortex, also called twisted light, is a beam of light with a helical wavefront, a dark central core, and quantized orbital angular momentum per photon.
Optical waveguide
An optical waveguide is a structure that guides light by confining it in a higher-index core, the principle behind optical fibers, integrated optics, fiber lasers, and waveguide sensors.
Optical-field-induced current in dielectrics
Optical-field-induced current in dielectrics is laser-driven current in an insulator, first shown in fused silica in 2012–2013, raising conductivity over 18 orders of magnitude within 1 femtosecond.
Optical-resolution photoacoustic microscopy
Optical-resolution photoacoustic microscopy (OR-PAM) is a photoacoustic imaging technique that images optical absorption in biological tissue, resolving single capillaries and cells to depths of about 1 mm.
Optically detected magnetic resonance
Optically detected magnetic resonance (ODMR) is a spectroscopy technique that detects magnetic resonance of spins through fluorescence changes, first reported in 1959 and now used for nanoscale magnetometry with diamond defects.
Optically levitated nanoparticle
An optically levitated nanoparticle is a nanoscale dielectric object, typically a silica sphere around 100 nm wide, held in vacuum by a focused laser beam for precision sensing.
Optically pumped magnetometer
An optically pumped magnetometer (OPM) is a magnetic field sensor that reads the Larmor precession of laser-pumped alkali vapor atoms, reaching femtotesla sensitivity comparable to SQUIDs.
Optically stimulated luminescence
Optically stimulated luminescence (OSL) is the light emitted by a material previously exposed to ionizing radiation when stimulated by light, used in dosimetry and sediment dating.
Optically stimulated luminescence dating
Optically stimulated luminescence (OSL) dating determines how long buried quartz or feldspar grains have been hidden from daylight, dating sediments from one year to several hundred thousand years old.
Optics
Optics is the branch of physics studying the behavior and properties of light and its interaction with matter, together with instruments like telescopes and microscopes.
Optics Express
Optics Express is a biweekly, gold open-access peer-reviewed journal covering optics and photonics. Launched in 1997 by the Optical Society of America, it is the most-cited journal in optics.
Optimal design (statistics)
Optimal design is a statistical method for choosing experiment settings, run allocations, or point weights so a criterion computed from the Fisher information matrix is optimized.
Optimal design of environmental monitoring networks
Optimal design of environmental monitoring networks is the statistical problem of choosing how many stations to operate and where, so measurements carry the most information per unit of budget.
Optimal extraction
Optimal extraction is an algorithm in astronomical spectroscopy, formulated by Keith Horne in 1986, that converts a two-dimensional detector image into a one-dimensional spectrum with the best possible signal-to-noise ratio.
Optimal fingerprinting
Optimal fingerprinting is a regression-based statistical method in climate science that detects climate change signals in observations and attributes them to forcings such as greenhouse gases.
Optimal stopping
Optimal stopping is the branch of probability theory that studies when to take a once-only action, such as selling an asset or exercising an option, to maximize expected reward.
Optimized norm-conserving Vanderbilt pseudopotentials
Optimized norm-conserving Vanderbilt (ONCV) pseudopotentials are norm-conserving pseudopotentials for plane-wave electronic-structure calculations, formulated by D. R. Hamann in 2013 to converge faster with smaller plane-wave basis sets.
Optimizely
Optimizely is an American digital experience company founded in 2009 by Dan Siroker and Pete Koomen, known for A/B testing, feature flags, and personalization; Episerver acquired it in 2020.
Optional stopping theorem
The optional stopping theorem, also called the optional sampling theorem, is a martingale result due to J. L. Doob, showing no quitting strategy can beat a fair game.
Optoelectronics
Optoelectronics (optronics) is the branch of physics dealing with devices that convert signals between light and electricity, such as LEDs, laser diodes, photodiodes, and solar cells.
Optogenetics
Optogenetics is a technique in which genetically modified neurons are switched on or off with light, which has transformed neuroscience and partially restored vision in a blind patient.
Optomagnetic switching
Optomagnetic switching is the reversal or control of a material's magnetization using ultrashort laser pulses alone, without an applied magnetic field, pursued for faster, lower-energy magnetic memory writing.
Optomechanical cooling
Optomechanical cooling uses light in an optical or microwave cavity to remove vibrational energy from a mechanical resonator, reducing its thermal motion toward the quantum ground state via radiation pressure.
Optomechanical crystal resonators
An optomechanical crystal cavity (OMCC) is a nanoscale semiconductor resonator patterned as a photonic and phononic crystal that confines light and gigahertz mechanical vibrations together, enabling microwave-to-optical quantum transduction.