Photonics Dictionary

A modified form of an image-retaining panel that can be used in subdued daylight. This is achieved by adding a layer of zinc oxide between the panel's phosphor layer and its rear electrode. The zinc...

A method used to compare two pictures of the same subject taken at different times. See image comparison.

Complex devices, often involving a computer, in which a photograph is scanned by a point of light, the amplitude of the electrical signal being modified electronically before being re-recorded on...

The technique that uses light to detect and analyze the antibodies produced by a specimen stained with an organic dye.

Immunohistochemistry (IHC) is a method for detecting antigens or haptens in cells of a tissue section by using labeled antibodies to bind specifically to their antigens. IHC is used for disease...

Qualitatively, the inverse of the amount of velocity produced by the application of a sinusoidal force to a system; therefore, if velocity is high, impedance at that point is low. Quantitatively,...

In the context of optical materials, the term "impurity level" refers to the presence of foreign atoms or molecules within the material that deviate from its regular or intrinsic composition. These...

That state determining that two waves of like frequency will travel through their maximum and minimum values of the same polarity simultaneously.

In vitro is a Latin term that translates to "in glass." In scientific contexts, particularly in biology and medicine, it refers to experiments or procedures conducted outside of a living organism,...

In vivo is a Latin term that translates to "within the living." In scientific contexts, particularly in biology and medicine, it refers to experiments or observations conducted within a living...

Flux incident per unit area of a surface.

The presence, within the body of the glass, of extraneous or alien material. See seed; striae.

The production of holograms initially from either conventional photographs or incoherent optical equipment.

The decrease in the refractive index at the center of a fiber's core, caused by certain fabrication techniques. Also called profile dip.

Generally, a rotatable table with scales marked in degrees. The fiducial marking also may be a vernier scale. The same scheme is applied to linear movement. Such devices are often applied to...

Metal used in components of the crystalline semiconductor alloys indium gallium arsenide (InGaAs), indium gallium arsenide phosphide (InGaAsP), and the binary semiconductor indium phosphide (InP)....

Induced pluripotent stem (iPS) cells are ordinary cells that are genetically reprogrammed to an embryonic stem cell-like state to allow the human cells to be used for therapeutic purposes....

Inductance is a fundamental property of an electrical circuit or component that describes its ability to store energy in a magnetic field when an electric current flows through it. It is typically...

A shutter in which the opening and closing times for a large aperture setting occupy a substantial fraction of the total exposure time so that apertures and time pair readings from an exposure meter...

Inertial confinement fusion (ICF) is a method of achieving nuclear fusion, a process where two atomic nuclei combine to release energy. In the case of inertial confinement fusion, the fusion reaction...

Inertial fusion energy (IFE) refers to a proposed method of generating electricity by harnessing the energy released from the fusion of light atomic nuclei, typically isotopes of hydrogen, through a...

Infrared radiation absorbed by crystals as a result of the excitation of lattice vibrations in which ions having opposite charges move relative to one another. These vibrations take place in a narrow...

An infrared source, set in a stationary position, that is used as a reference in certain navigational systems.

An infrared camera, also known as a thermal imaging camera or IR camera, is a device that captures and visualizes the infrared radiation emitted by objects, revealing temperature variations across...

An infrared detector is a device that is used to detect and measure infrared radiation, which lies beyond the visible spectrum of light. These detectors are utilized in various applications,...

An infrared lens is an optical component specifically designed and optimized for transmitting, focusing, or manipulating infrared (IR) radiation within the infrared spectrum. These lenses are used in...

An infrared light source is a device that emits light in the infrared spectrum, which lies beyond the visible spectrum of light. Infrared light has longer wavelengths than visible light and is...

An infrared light-emitting diode (IR LED) is a semiconductor device that emits infrared light when an electric current passes through it. Similar to standard LEDs that emit visible light, IR LEDs are...

The process of mapping the infrared emittance of an area through the use of an infrared detector and related scanning instrumentation to produce thermal images that are then recorded on photographic...

A direct method of measuring refractive index that works best with flat-surfaced samples (i.e., those that are not dependent on special prism shapes) and produces data that are uniquely sensitive to...

Infrared optics refer to optical components and systems designed to manipulate and control infrared (IR) light, which lies beyond the visible spectrum. These components are crucial for various...

The range of materials that, unlike glass, may be used in the infrared. Water-soluble salts, such as cesium iodide, and other substances such as arsenic sulfide, selenium, thallium bromide-iodide and...

A phosphor, such as sulfide or selenide, that can be excited to luminescence by incident infrared radiation simultaneous to or following its excitation by visible radiant energy.

An optical system used to collect infrared energy from a scene using scanning optics with a point or line detector, as compared with a fixed optical system with a full two-dimensional detector array.

A device that combines electronic and optical techniques to form a monitored infrared signal between 1 and 14 µm. It contains an internal modulator to amplitude-modulate the output signal, an...

A spectrophotometer having a prism or, more frequently, a grating for the study and recording of infrared spectra. It usually consists of a radiation source such as a Nernst glower, a monochromator,...

A vidicon that has a photoconductive surface that can be excited by infrared radiation.

Infrared (IR) refers to the region of the electromagnetic spectrum with wavelengths longer than those of visible light, but shorter than those of microwaves. The infrared spectrum spans wavelengths...

An InGaAs photodiode refers to a photodetector device that is constructed using a semiconductor material composed of a combination of indium (In), gallium (Ga), and arsenic (As). The term InGaAs...

Injection locking, also known as injection-phase locking or injection-phase control, is a phenomenon in which a weak signal is synchronized with a stronger signal due to the injection of energy or...

Injection molding is a manufacturing process used to produce parts by injecting molten material into a mold. It is widely used for creating a variety of plastic products, but it can also be used with...

Inline inspection involves performing quality checks, measurements, or tests on products or materials while they are being produced or processed, rather than inspecting them separately in a dedicated...

I/O stands for input/output. In computing, it refers to the communication between a computer system or program and its external environment, including peripherals, storage devices, networks, and...

The total optical power loss caused by the insertion of an optical component such as a connector, splice or coupler into a fiber optic system. See attenuation.

A method that produces low-loss optical fibers. A glass tube rotates while reactants pass through the tube and heat is externally applied by a burner that traverses the tube. The oxidizable vapors in...

Instantaneous field of view (iFOV) is a term commonly used in the context of remote sensing, imaging systems, and optical instruments. It refers to the specific portion of a scene that an optical...

The tendency to adjust an instrument such as a microscope so that the viewed image appears much closer than infinity.

With respect to color photography, the measurement of the way the color film modulates the radiant flux in the optical system containing the film.

A reflection hologram using multiple color lasers that integrates various graphical techniques to allow the display of three-dimensional images of live objects in motion, as well as outdoor scenes,...