|
An optical device used to disperse light into a spectrum.
It consists of a large number of narrow, closely spaced lines ruled either on glass to form a transmission grating or on polished metal to form a reflection grating.
Typically there are several thousand rules per centimetre. Interference between the beams of light created by diffraction at each slit result in the dispersion of the light with wavelength. Diffraction gratings can produce very high dispersion spectra of good quality,
and are used for this purpose in astronomical spectrographs.
|