Photonics Dictionary

Chip-on-board (COB) lights refer to a type of LED lighting technology where multiple LED chips are directly mounted onto a substrate, typically a printed circuit board (PCB), without the need for...

A light beam whose electric vectors can be broken into two perpendicular elements that have equal amplitudes and that differ in phase by l/4 wavelength.

A light source that is capable of producing radiation with waves vibrating in phase. The laser is an example of a coherent light source.

A means of illumination from which the infrared component has been removed by absorption or reflection filters within the condenser system.

An incandescent or fluorescent lamp whose emittance spectrum resembles that of daylight.

A device used to create a light output that exceeds light input, the energy being provided by an electric field. It consists of a photoconductive layer with an electroluminescent layer between plates...

A light beam whose electric vectors are broken into two elements of unlike amplitudes that are perpendicular to each other and that differ in phase by values other than 1, 3/4, 1/2, 1/4, etc.,...

A bundle of optical fibers arranged randomly for the purpose of transmitting energy, not an image.

An instrument designed to give a visual indication to the pilot when the plane has strayed from a specific flight path.

A tube containing mercury vapor and lined with a phosphor. When current is passed through the vapor the strong ultraviolet emission excites the phosphor, which emits visible light. The ultraviolet...

A photometer used to measure sky brightness and polarization associated with zodiacal light, background starlight, F-region airglow and spacecraft corona.

Radiation consisting of more than a single wavelength in the visible region of the spectrum.

The portion of a reproduced image having the greatest luminance.

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

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...

An infrared source combined with reflecting projection optics to illuminate a target making it visible when observed through an infrared viewing device.

A filter that transmits infrared and ultraviolet but is opaque to visible radiation.

A scattering photometer using scattered light in the solid angle 4.51+0 19° with respect to the forward direction, and an impactor with a rectangular jet. Scattered light intensities of entering...

A liquid crystal light valve (LCLV), also known as a spatial light modulator (SLM), is an optical device that modulates the intensity, phase, or polarization of light passing through it using liquid...

An optical fiber with a hollow core filled with a liquid material that has a higher refractive index than the solid surrounding it.

A fiber optic component or system designed in such a way that it can be operated by people without specialized knowledge of the field.

Instrumentation designed to permit the perception, recording or measurement of scenes under conditions of low incident illumination.

Machine vision lighting refers to the use of specific lighting techniques and equipment in the field of machine vision, which is a technology that enables machines to capture and interpret visual...

A lamp that has mercury in a tube or bulb that has first been evacuated. The electricity travels through the vapor between the electrodes and produces a blue-green light that is rich in ultraviolet...

A device to modulate spatially a collimated coherent beam of light with input data in optical data processing. It uses a photocathode mounted on a microchannel plate, which amplifies an electron...

Light consisting of a single wavelength or a very narrow band of wavelengths.

A fiber optic bundle split along its length with the ends of the fibers extending separately to illuminate different points with a single light source.

A light source, such as the sun or an incandescent lamp, that freely penetrates ordinary glass bulbs and emits in the near-ultraviolet (wavelengths ranging from about 300 to 400 nm). A mercury vapor...

An organic light-emitting diode (OLED) is a type of light-emitting diode (LED) technology that utilizes organic compounds to produce light. OLEDs are commonly used in display technologies, such as...

A source made to glow by electrons that are produced either electrically or by isotopes of various elements.

A light beam whose electric vectors all vibrate in a single fixed plane.

1. With respect to angular subtense, a source of light, such as a star, that is very small. In a lab, a point source may be simulated by imaging a large source onto and through a pinhole, or by...

Quantum dot light-emitting diode (QLED) is a display technology that utilizes quantum dots, which are semiconductor nanocrystals, to produce vibrant and high-quality images. QLED displays are...

A lamp with a quartz envelope that transmits radiation generally rich in the ultraviolet.

Single wavelength source with a larger linewidth often containing multiple longitudinal modes.

A very uncommon lamp in which a tungsten electrode is heated to incandescence by a radio-frequency electrical current.

An exposure meter that indicates the amount of light reflected from the subject of interest.

The re-emission of absorbed energy, having the same wavelength as the incident energy, in an arbitrary direction from a particle because of an energy level transition within the material.

A circular lamp or bundles of optical fibers placed around the perimeter of an objective lens to illuminate the object field below it.

Filtered light to which photographic or other photosensitive materials are not responsive; used to illuminate darkrooms when film is being processed. The color of the filter varies according to the...

That theory that treats the light field as a single scalar field rather than as two coupled vector fields.

A specific type of filter designed to reduce the amount of light scattered by reflections from the edges of optical components or mounts, or from irregularities on the optical surfaces.

Any material that derives its energy from chemically or electrically induced reactions; isotope or radium excitation is used to form the glow in luminescent watch or clock hands.

An electronic flash tube in which the flash recurs at a frequency extending to many thousands per second. A stroboscopic light source is a short-flash light source.

Silicon carbide (SiC) light-emitting diodes (LEDs) are semiconductor devices that emit light when an electric current is applied to them. These LEDs are made using silicon carbide as the...