Photonics Dictionary: I

The formation of a hologram by single reference-beam interferences with waves that are diffracted or scattered from a small object.

A device used to accelerate the electrons in a free-electron laser by supplying electrical energy to the electron beam through a series of transformers.

A spectral line of an internal standard; used to compare radiant energy of the line being analyzed.

Sharp and narrow absorption lines found in the spectra of stars. They result from the absorption of a part of a star's emittance by interstellar gases.

A thermosetting material used in the jacket of fiber optic cables.

1. Lines of the same color. 2. A term used in photoelastic stress analysis to refer to the interference fringes produced in birefringent materials.

A photometric instrument used to measure the illumination falling on a surface. It may be photoelectric or visual.

An image intensifier, also known as an image intensification tube or image intensification device, is a specialized electronic device used to amplify low-light-level images to make them visible to...

A camera tube widely used in television broadcasting. It consists of three sections within a single vacuum envelope. 1. A photosensitive film sometimes called the photocathode. The scene to be...

A measure of the closeness with which an optical image is capable of resembling the original object. The factors that affect image quality are lens aberrations, diffraction, dirt and stray light...

An eyepiece having a special prism arrangement linked to a micrometer screw to allow reading of the angular relations between the two prism segments to be varied. When the prism faces are parallel,...

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...

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...

A material, often a liquid or cement, whose refractive index is nearly equal to the fiber's core index, used to reduce Fresnel reflection from a fiber end face.

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...

The light formed by visible radiation that, in traveling from light source to object, undergoes one or more reflections. In microscopy, it is the light that falls on the object at right angles to the...

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)....

An InGaAs (indium gallium arsenide) camera is a type of imaging device that utilizes InGaAs sensors to capture images in the near-infrared (NIR) spectrum. InGaAs is a semiconductor material that is...

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....

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...

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...

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.

Broadening of a laser's spectral linewidth when the resonance frequencies of the atoms (or molecules) of the medium are not homogeneous on the same transition. An example is Doppler broadening.

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...

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,...

An optical circuit, either monolithic or hybrid, composed of active and passive components, used for coupling between optoelectronic devices and providing signal processing functions.

A standard direct-readout vidicon tube linked by fiber optics to an intensifier for increased sensitivity.

Describing the standard television method of raster scanning in which the image is the product of two fields, each of which is a series of successively scanned lines separated by the equivalent of...

The internet of things (IoT) refers to a network of interconnected physical devices, vehicles, appliances, and other objects embedded with sensors, actuators, software, and network connectivity....

A laser in which the transition involved in stimulated emission of radiation takes place between two levels of an ionized gas. The gases are electrically excited in a container called a plasma tube,...

Generally, any radiation that can form ions, either directly or indirectly, while traveling through a substance.

A mechanical device designed to smoothly vary the effective diameter of a lens, thereby controlling the amount of light allowed through.

The adjustable membrane located just in front of the crystalline lens within the eye. The iris gives the eye its color. See also iris diaphragm.

Lines of equal atmospheric attenuation in a laser beam.

The slight difference in wavelength of an element's given spectral line observed in comparing different isotopes of that element.