Photonics Dictionary: I

An instrument in which an object's image, produced by a lens of known focal length, is used to determine the object's distance from the instrument when its size is known, or the object's size if the...

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

A type of refractometer designed to measure the refractive indices of liquids. A section of the instrument is immersed into the sample being measured.

An exposure meter designed to measure the light striking an object and used at a suitable location in a scene.

A superconducting bolometer, operating at very low temperatures, that is used to detect infrared radiation.

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,...

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...

An instrument that employs the interference of lightwaves to measure the accuracy of optical surfaces; it can measure a length in terms of the length of a wave of light by using interference...

Also known as the Bragg spectrometer. A system used for the x-ray analysis of crystal structure. In the instrument, a homogeneous beam of x-rays is directed on the known face of a crystal and the...

A direct recording photometer that is designed to scan a photographic negative to determine its points of isodensity.

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...

In optics, the term image jump refers to a displacement or shift in the apparent position of an image when a change occurs in the optical system. This phenomenon is often observed in certain types of...

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,...

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...

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...

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-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 (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...

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...

A special form of microscope that utilizes interference for observing and measuring the phase and optical thickness in completely transparent objects and specimen. The object is placed in one beam...

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...

Loss intrinsic to the fiber caused by parameter (core dimension, profile parameter) mismatches when two nonidentical fibers are joined.

Ion-beam sputtering (IBS) is a physical vapor deposition (PVD) technique used for depositing thin films onto substrates. It involves bombarding a target material with a beam of energetic ions,...

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

An enclosure for a calorimeter that allows measurement of unusually low quantities of power and energy.

A spectroscopic technique in which an excitation band absorbs laser energy resulting in an electronic transition. The isotopic species may then be measured using a time of flight mass spectrometer....