Grating spectrometer

A grating spectrometer uses the optical diffraction at a grating to interfere with the light ( diffraction grating ).

The light arrives at a slit-shaped light entrance via optical elements (lenses or light guides). The alignment of the slit corresponds to the alignment of the furrows / lines of the diffraction grating. The diffraction / interference creates the spectrum.

In the past, photographic plates were used as receivers, in which the spectrum was evaluated based on the blackening. Secondary electron multipliers and semiconductor detectors that convert photons into electrical signals are used today for qualitative analysis of spectra.

If the light is narrow-band selected at a further slit and only a small wavelength range is recorded, this is called the monochromator principle .

With a polychromator , larger spectral areas are recorded simultaneously. Depending on the optical setup, several exit slits and secondary electron multipliers or linear semiconductor detectors can be used. In Echelle polychromators be CCD - or CID-area detectors used.

See also: optical spectrometers and monochromators , for a more general consideration