Photonics Dictionary

A type of additive color photography using a lenticular structure impressed on a film base and a camera lens with a filter having three sectors of red, blue and green. Exposure of the film through...

An LED, or light emitting diode, is a semiconductor device that emits light when an electric current passes through it. LEDs are widely used in various applications due to their energy efficiency,...

The reddish/purple color that results when equal amounts of blue and red are combined so that no one wavelength dominates.

With respect to television, that part of a color television circuit that combines the I, Q and Y signals, and changes them into single red, green and blue signals applied to the picture-tube grids.

An electric arc that is formed in mercury vapor through which an electric current flows. The intensity of the illumination of the arc depends mostly on its design and the conditions under which it...

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...

Mie scattering, named after the German physicist Gustav Mie, refers to the scattering of electromagnetic radiation (such as light) by spherical particles. Unlike Rayleigh scattering, which is...

Multispectral imaging is a technique that involves capturing and analyzing images at multiple discrete spectral bands within the electromagnetic spectrum. Unlike hyperspectral imaging, which acquires...

A color whose hue is not produced by a single wavelength in the visible spectrum, but is instead produced by mixing the longest (red) and shortest (blue) wavelengths of the spectrum such as any...

Black and white film that is sensitive to green, blue and violet light but not to red light.

Phototherapy is a medical treatment that involves the use of light to treat various conditions, particularly those related to the skin or mood disorders. There are different types of phototherapies,...

A pixel, short for "picture element," is the smallest controllable element of a digital image or display. It is a fundamental unit that represents a single point in a raster image, which is a grid of...

A set of three colored lights which, when mixed, give the sensation of white light. The set used in color television, for example, is red, green, blue (RGB).

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...

Rayleigh scattering is a phenomenon that occurs when light waves interact with particles or molecules that are much smaller than the wavelength of the light. It is named after the British scientist...

Also known as display primaries. Colors formed by a television receiver that are of constant chromaticity and variable luminance, and that, mixed in certain proportions, form other colors. Red, green...

An aberration that remains after primary color is corrected. Primary color causes the back focus of a lens to vary with wavelength; for example, blue light comes to focus closer to the lens than...

Three filters used in making a color print of a color negative, red, green and blue-violet, respectively. Each filter transmits about one-third of the visible spectrum onto the print.

A type of color-generating cathode-ray tube that uses a shadow mask, a thin perforated electrode, located close to the display screen. Each hole in the mask coincides with a triad of three phosphor...

Cyan, magenta and yellow. They are called subtractive because they each subtract one color by absorbtion and reflect the two others of the red, green, blue color primaries. Cyan absorbs red, magenta...

A liquid crystal display using the material in its supertwisted nematic phase; the birefringence of the liquid crystal results in a characteristic yellow or blue color, unless corrected.

The series of interference bands that appear in the spectrum when a specified glass plate is inserted into a spectroscope, from the side of the blue portion of the spectrum, so that the plate...

Thermography is a technique that involves the use of an infrared imaging device, called a thermal camera or infrared camera, to detect and visualize the infrared radiation emitted by objects. This...

Integral densities that are measured relative to arbitrarily selected red, green and blue filters.

In a color cathode-ray tube, a grouping of three color dots (red, blue and green) that represent one pixel in the final image.

The basis of color vision in the human eye. Three types of cones have been identified, each having a unique spectral response (red, green and blue).

A color-television viewing system with three kinescopes, three lenses and three deflection yokes used to form the red, green and blue images required for a tricolor television projection.

The effect by which sufficiently small particles will scatter blue light at right angles to the incident beam. This scattered light is completely linearly polarized.