Photonics Dictionary

An instrument that produces an intense, tightly focused beam of ions to stimulate emissions from a minute section of a sample undergoing spectroscopic analysis. The ion beams found in microprobes are...

The pattern of microwave field intensity that can be obtained by detecting the minute expansion of a microwave absorber slab when heated by the microwave field, accompanied by moiré interference of a...

A mid-infrared camera is a type of imaging device designed to capture images in the mid-infrared (mid-IR) spectral range, typically spanning wavelengths from approximately 3 to 12 µm. This...

MWIR stands for mid-wave infrared, referring to a specific range of wavelengths within the infrared spectrum. Infrared radiation is categorized into three main regions based on wavelength:...

Mie scattering, named after the German physicist Gustav Mie, refers to the scattering of electromagnetic radiation (such as light) by spherical particles. Unlike Rayleigh scattering, which is...

Mode locking is a technique used in optics and laser physics to generate short pulses of light with extremely high peak powers. In mode locking, the phases of different longitudinal modes (specific...

Mode-locking is a technique used in lasers to produce ultrashort pulses of light with durations on the order of picoseconds, femtoseconds, or even attoseconds. This method synchronizes the phases of...

A monochromator is an optical instrument used to isolate and select a narrow range of wavelengths from a broader spectrum of light. The term monochromator is derived from "monochromatic," meaning...

Simulation of radiative transfer in which each photon is generated by a source and its path through the medium is statistically simulated with absorption and scattering probabilities as well as with...

Spectroscopy characterized by the Mossbauer effect - recoilless emission and absorption of nuclear gamma radiation- which investigates miniscule changes in the energy levels of atomic nuclei in...

A process involving the interaction (absorption, emission or both) of two or more photons with a molecular entity.

Nanoplasmonics is a branch of nanophotonics that focuses on the study and manipulation of optical phenomena at the nanoscale using plasmonic materials and structures. Plasmonics deals with the...

A near-infrared (NIR) camera is an imaging device designed to capture images in the near-infrared region of the electromagnetic spectrum. The near-infrared spectrum typically extends from about 700...

A near-infrared (NIR) spectrometer is an analytical instrument used to measure the absorption, transmission, or reflection of light in the near-infrared region of the electromagnetic spectrum....

A monitoring technique used to measure the oxygen saturation levels in the brains of patients, commonly in operating room and neonatal intensive care unit settings. The technique, which is based on...

Near-infrared spectroscopy (NIRS) is a non-invasive analytical technique that uses the near-infrared region of the electromagnetic spectrum to study the absorption of light by molecules in a sample....

A coating applied to a neutral density glass that is designed to reduce the amount of light evenly across the transmitted light spectrum with no color distortion. These coatings are designed to...

The nondestructive analysis and recording of industrial components based on the absorption of relatively low-energy neutrons by material having low atomic numbers. The visible image formed by the...

A nitrogen vacancy (NV) refers to a specific type of defect or impurity in a crystal lattice where a nitrogen atom replaces a carbon atom adjacent to a vacancy (an empty lattice site) in the diamond...

A nonradiative transition refers to a process in which an electron or an atom undergoes a change in its energy state without emitting a photon. In contrast to radiative transitions, where a photon is...

A phenomenon, exploited for medical imaging, in which the nuclei of material placed in a strong magnetic field will absorb radio waves supplied by a transmitter at particular frequencies. The energy...

A light absorbing material applied to ground optical surfaces during the process of making that surface non reflective. Such material should have a refractive index as high as that of the underlying...

Optical cements and adhesives are specialized materials used in the assembly and bonding of optical components in optical systems. These materials are designed to provide secure and durable bonds...

A measure of the transmittance through an optical medium. Optical density equals the log to the base 10 of the reciprocal of the transmittance. where τλ is transmittance. In spectroscopy,...

An optical filter is a device that selectively transmits or blocks specific wavelengths, or colors, of light. Optical filters are used to control the spectral content of light in various...

Optical glass refers to a type of glass specifically engineered and manufactured for use in optical components and systems, such as lenses, prisms, mirrors, and filters. Optical glass is...

Optical materials refer to substances or compounds specifically chosen for their optical properties and used in the fabrication of optical components and systems. These materials are characterized by...

Optical noise refers to undesirable fluctuations or disturbances in an optical signal that can affect the quality or integrity of the transmitted information. This type of noise is particularly...

The process whereby the number of atoms or atomic systems in a set of energy levels is changed by the absorption of light that falls on the material. This process raises the atoms to specific higher...

An optical testing instrument is a device or system used to evaluate and measure the performance, quality, and characteristics of optical components, systems, and devices. These instruments play a...

The process by which an atomic system changes from one energy level to another by either the emission or absorption of visible, infrared or ultraviolet radiation.

A laser in which stimulated emission is triggered by the absorption by electrons of light from an auxiliary source such as a flash lamp, or another laser. See optical pumping.

The area of optics that deals with the interaction of light with a given material. The optical properties of material are generally described by the absorption, transmission, reflection, and...

Optoacoustic, or photoacoustic, refers to a phenomenon and related techniques that involve the generation of acoustic waves in a material induced by the absorption of light. The term "optoacoustic"...

Optofluidics is an interdisciplinary field that combines principles from optics and fluidics to create devices and systems that integrate the manipulation of light and fluids. This field focuses on...

Any organic substance, that when dissolved in appropriate liquid based solvents will absorb and emit electromagnetic radiation in the near ultraviolet, visible and near infrared spectral regions....

The emission of gas or de-aeration due to thermal variations and often occurring in a vacuum. In a cleanroom, contamination from the spontaneous emission of absorbed particles.

A Peltier cooler, also known as a thermoelectric cooler (TEC) or thermoelectric module, is a solid-state device that uses the Peltier effect to transfer heat between two electrical junctions. It can...

The term perovskite refers to a specific crystal structure commonly found in various materials. Perovskite structures have a cubic arrangement of oxygen ions, forming a framework within which other...

A microscope that has an annular stop in the lower focal plane of the condenser, and a quarter-wave retarding and absorbing ring in the upper focal plane of the objective that just fills the image of...

Periodic interruptions of a light beam incident on an absorbing medium that produce heat, expansion and acoustic wave generation. Since the amplitude of this wave is proportional to the absorbed...

A device for measuring absorption coefficients in which a confined, nonabsorbing gas fills the space inside the cell between the two windows, which are made from a weakly absorbing medium.

Abbreviated PAI. An imaging modality with a hybrid technique based on the acoustic detection of optical absorption from endogenous chromophores or exogenous contrast agents. Light is absorbed by the...

A method for obtaining the optical absorption spectra of solids, semisolids, liquids and gases. PAS is inherently insensitive to reflection or scattering from the sample, analyzes opaque samples and...

Photobleaching is a phenomenon in which the fluorescence of a fluorophore (a fluorescent molecule or dye) is permanently reduced or eliminated upon prolonged exposure to light. This process occurs...

Photocathodes are specialized materials or surfaces that exhibit the photoelectric effect, wherein the absorption of photons leads to the emission of electrons. When photons with sufficient energy...