The Collaborative International Dictionary
Grating \Grat"ing\, n. [See 2d Grate.]
A partition, covering, or frame of parallel or cross bars; a latticework resembling a window grate; as, the grating of a prison or convent.
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(Optics) A system of close equidistant parallel lines or bars, esp. lines ruled on a polished surface, used for producing spectra by diffraction; -- called also diffraction grating.
Note: Gratings have been made with over 40,000 such lines to the inch, but those with a somewhat smaller number give the best definition. They are used, e. g., to produce monochromatic light for use in optical instruments such as spectrophotometers.
pl. (Naut.) The strong wooden lattice used to cover a hatch, admitting light and air; also, a movable Lattice used for the flooring of boats.
Wiktionary
n. (context physics English) a surface having a large number of closely spaced lines or slits; used to produce optical spectra by mutual interference
WordNet
n. optical device consisting of a surface with many parallel grooves in it; disperses a beam of light (or other electromagnetic radiation) into its wavelengths to produce its spectrum [syn: grating]
Wikipedia
In optics, a diffraction grating is an optical component with a periodic structure, which splits and diffracts light into several beams travelling in different directions. The emerging coloration is a form of structural coloration. The directions of these beams depend on the spacing of the grating and the wavelength of the light so that the grating acts as the dispersive element. Because of this, gratings are commonly used in monochromators and spectrometers.
For practical applications, gratings generally have ridges or rulings on their surface rather than dark lines. Such gratings can be either transmissive or reflective. Gratings which modulate the phase rather than the amplitude of the incident light are also produced, frequently using holography.
The principles of diffraction gratings were discovered by James Gregory, about a year after Newton's prism experiments, initially with items such as bird feathers. The first man-made diffraction grating was made around 1785 by Philadelphia inventor David Rittenhouse, who strung hairs between two finely threaded screws.See:
- Thomas D. Cope (1932) "The Rittenhouse diffraction grating". Reprinted in: (A reproduction of Rittenhouse's letter re his diffraction grating appears on pp. 369–374.) This was similar to notable German physicist Joseph von Fraunhofer's wire diffraction grating in 1821.See:
Diffraction can create "rainbow" colors when illuminated by a wide spectrum (e.g., continuous) light source. The sparkling effects from the closely spaced narrow tracks on optical storage disks such as CD's or DVDs are an example, while the similar rainbow effects caused by thin layers of oil (or gasoline, etc.) on water are not caused by a grating, but rather by interference effects in reflections from the closely spaced transmissive layers (see Examples, below). A grating has parallel lines, while a CD has a spiral of finely-spaced data tracks. Diffraction colors also appear when one looks at a bright point source through a translucent fine-pitch umbrella-fabric covering. Decorative patterned plastic films based on reflective grating patches are very inexpensive, and are commonplace.
Usage examples of "diffraction grating".
At one moment it would be as flat and featureless as polished steel then it would become flooded with iridescent, rainbow colors, behaving like a giant diffraction grating.
Its metallic limbs gleamed with the rainbow iridescence of a diffraction grating.
I saw that a shaft of red light, split out and deflected by his prism, shone through a diffraction grating and cast an angular pattern of dots and lines on a scrap of smooth plastic behind.
The spines of his nopal sparkled like a diffraction grating in the glare of the lights along the marquee.
The diffraction grating bends the light, but the different frequencies bend to different amounts.
If they could make a diffraction grating that big, they could make a mirror that big.
Larger aperture and, for the spectral part, a dragonskin diffraction grating—.
He spun it so that the internal diffraction grating caught the light.
It gleamed like a diffraction grating as a beam of direct sunlight caught it.
It was a thermo needle beam which was propagated in a burst of high-peak intensity thin a force-field diffraction grating so that it was split up into tens of thousands of 1-mm beams.
Her teeth were plated with metal cut in a diffraction grating which filled her mouth with rainbows as the lights flashed.