Photonics Dictionary: I

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...

A photoconductor that demonstrates increased conductivity during its exposure to infrared radiation.

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,...

1. A thin parallel plate of material that transmits in the infrared region. See infrared optical material. 2. A spectral region (of the infrared) in which the atmosphere transmits.

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...

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.

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...

A semiconductor diode operating in either a coherent or incoherent mode that is used as a near-infrared or visible source in triggering light-activated devices.

A method of producing high-quality plastic optics in large volumes by injecting the heated, liquified plastic at high pressure into a tooled mold with polished chromium stainless steel inserts to...

A process by which a plastic cell is molded around a glass lens or lenses to create a mount, eliminating the metal barrel and the need for glass-to-metal seals.

In a camera, the movement of one or more lenses behind the front lens, rather than of the front lens itself, to bring the subject into focus. Because internal focusing does not require the front lens...

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...

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...

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,...

Multiple, interconnected circuit elements, contained on or in a common substrate, that function as a unit and not separately.

An infrared detector mounted directly on the cold finger of the Dewar cooler rather than at the interface of Dewar and cooler, resulting in decreased size and power consumption and greater...

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

Integrated photonics is a field of study and technology that involves the integration of optical components, such as lasers, modulators, detectors, and waveguides, on a single chip or substrate. The...

Integration time, in the context of optics, imaging systems, and sensor technology, refers to the duration over which a sensor collects and accumulates incoming light or signal. It is a crucial...

An intensified charge-coupled device (ICCD) camera is an advanced imaging device that combines the capabilities of both an image intensifier and a charge-coupled device (CCD) sensor to achieve...

An interferometer that functions by first detecting the light striking each aperture and then combining the two detector outputs. With an intensity interferometer, the primary collectors need not be...

The process in which the electron beam of a cathode-ray tube varies in intensity in accordance with the magnitude of the signals it receives.

A type of fiber optic sensor that responds to a change in the intensity of received light caused by the displacement or other phenomena being measured.

An interband cascade laser (ICL) is a type of semiconductor laser that operates based on interband transitions between energy bands in a semiconductor material. Unlike traditional semiconductor...

A lens that has a mount, usually bayonet or screw type in design, that can be used on a camera in place of lenses with the same mounting. This allows one camera body to be used with lenses of...

1. The additive process whereby the amplitudes of two or more overlapping waves are systematically attenuated and reinforced. 2. The process whereby a given wave is split into two or more waves by,...

Heat measurement method in which the sample is made part of the interferometer and the temperature increase is determined by measuring the change in optical pathlength through the material. By moving...

Interferometric modulator display (IMOD) is a type of display technology used in electronic devices, known for its energy efficiency and ability to produce high-quality reflective color displays....

Interlayer attraction refers to the attractive forces between adjacent layers of atoms or molecules in a material, particularly in layered structures such as van der Waals solids, graphene, and...

The effect in which photons are absorbed and excite the electrons; the electrons move from the valence band to the conduction band (intrinsic photoeffect), from the valence band to impurity levels or...

The creation of free electrons within a solid by the absorption of a sufficient amount of photons. The effect produces an increase in the conductivity of the solid.

A nonoptical surface, within lenses and lens mounts, that contributes largely to flare by reflecting light into the image space. As a result, such surfaces, so located, are finished with a dull...

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....

Measures the refractive indices axially from the fiber profile. Microscopy technique provides an interferogram with high contrast with demonstrated improvements in relation to the Pluta two-beam...

That distortion resulting from dispersion of the group velocity of a propagating mode. It is the only distortion occurring in single-mode waveguides.

A lens that is implanted within the eye to replace the eye lens, which has been removed because of cataract or other defect.

Intravital microscopy is an imaging technique used to visualize biological processes within living organisms, typically in real-time. Unlike traditional microscopy, which involves the examination of...

The changing of the kinetic energy of a mobile electron into radiant energy, as in formation of x-rays.

Any problem that requires retrieval of the distribution of some internal properties, such as temperature concentration, etc., from remotely sensed data.

An atom that has gained or lost one or more electrons and, as a result, carries a negative or positive charge.

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,...

A technique for improving the structure density of thin-film coatings by bombarding the growing film with accelerated ions of oxygen and argon. The kinetic energy then dissipates in the film, causing...