Spectrograph
A spectrograph is an optical instrument that breaks down light of different wavelengths into its spectrum (ie into its different colors) and registers the generated spectrum using suitable detectors . The breakdown of light according to its wavelength is done with the help of optical elements that have dispersion properties, usually either a prism , a diffraction grating or a so-called grism , which combines the grating and prism in one element.
Spectrographs serve, among other things, as an observation device in astronomy , which splits the light from stars or galaxies emerging from a telescope into its spectrum and directs it to a detector.
In the past, such detectors were mostly photo plates and films . Today mainly CCD elements or lines of photodiodes are used for the purpose of detecting the spectrum generated by the spectrograph.
Instruments for spectroscopy , the visual observation of spectra, are called spectroscopes .