What is the function of a diffraction grating?

A diffraction grating serves the purpose of separating light into its component wavelengths, which is known as dispersion. When light encounters a diffraction grating, which consists of a series of closely spaced slits or grooves, it diffracts, or bends, as it passes through or reflects off the grooves. This bending causes different wavelengths of light to spread out and form distinct patterns.

Each wavelength of light is diffracted at a different angle, leading to the formation of spectra. For example, white light, which contains various wavelengths (colors), will be separated by a diffraction grating into a rainbow-like spectrum, revealing the individual colors of light such as red, orange, yellow, green, blue, and violet. This property is crucial in various applications, including spectroscopy, where it is used to analyze the composition of light sources and materials.

The other options refer to different functions: magnification and focusing are associated with lenses and microscopes, while improving image contrast can involve various techniques not specific to diffraction gratings.