Glossary Of Terms

Welcome to the Optronic Laboratories glossary of terms! Below you will find a list of the most commonly used terms used throughout the website. 

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Current Source
An electronic circuit that delivers or absorbs an electric current which is independent of the voltage across it

Detector Spectral Response

Diffuse Spectral Reflectance
The reflection of light or other waves or particles from a surface such that a ray incident on the surface is scattered at many angles rather than at just one angle as in the case of specular reflection

Foot Candle
A unit of illumination equal to that given by a source of one candela at a distance of one foot (equivalent to one lumen per square foot or 10.764 lux)

Foot Lambert
A unit of luminance that equals 1/π candela per square foot, or 3.426 candela per square meter

Integrating Sphere
An optical component consisting of a hollow spherical cavity with its interior covered with a diffuse white reflective coating, with small holes for entrance and exit ports. Its relevant property is a uniform scattering or diffusing effect

Internal Quantum Efficiency (IQE)
The ratio of the number of charge carriers collected by the solar cell to the number of photons of a given energy that shine on the solar cell from

Wavelengths from about 700 to 10,000 nanometers

An LED that emits infrared light

The amount of light incoming to a certain point from possibly all directions. This includes the amount of energy emitted at each wavelength from a radiant sample such as an LED, a laser or the sun. From that data, more specific intensity values can be calculated.

A semiconductor light source that emits light when current flows through it

The SI derived unitof illuminance, measuring luminous flux per unit area

The scientific study of measurement

Wavelengths from about 750 to 2500 nanometers

An organic light-emitting diode, also known as an organic EL diode, is a light-emitting diode in which the emissive electroluminescent layer is a film of organic compound that emits light in response to an electric current

An instrument for measuring the intensity of light

Power Supply
An electrical device that supplies electric power to an electrical load. The primary function of a power supply is to convert electric current from a source to the correct voltage, current, and frequency to power the load

Radiance is the amount of light incoming to a point from a single direction.

A device for measuring the radiant flux of electromagnetic radiation

The measure of the proportion of light or other radiation striking a surface which is reflected off it

Source Spectral Analysis

Spectral Illuminance

Spectral Irradiance
The irradiance of a surface per unit frequency or wavelength, depending on whether the spectrum is taken as a function of frequency or of wavelength

Spectral Luminance

Spectral Radiance
The radiance of a surface per unit frequency or wavelength, depending on whether the spectrum is taken as a function of frequency or of wavelength

Spectral Transmittance
The ratio of the transmitted power I(λ) to the incident power I0(λ) in a small interval of wavelength around the center wavelength λ and in a given (sufficiently small) solid angle of aperture

A scientific instrument used to separate and measure spectral components of a physical phenomenon

A light measurement tool that is able to measure both the wavelength and amplitude of the light emitted from a light source

Specular Reflectance
The ratio of the reflected light by a boundary interface to the incident light

Specular Spectral Reflectance

Total luminous Flux
A measure of the total amount of visible light emitted by a lamp

Total Spectral Flux
A measure of how quickly the power spectrumof a signal is changing, calculated by comparing the power spectrum for one frame against the power spectrum from the previous frame

Wavelengths from about 10 to 380 nanometers

Wavelengths from about 380 to 700 nanometers