Spectrometer by optical design

Optical spectrometers are often based on a Czerny-Turner setup. The light enters through an entrance slit and is directed onto an optical grating via a mirror. At this point, the light is spectrally split. A focus mirror focuses the slit onto the detector.

In transmissive spectrometers, the light beam is not reflected at the grating, but is guided through a transmission grating or prism.

FT spectrometers – Fourier transform spectrometers have an interferometer as a central component, as the spectrum is calculated by a Fourier transformation of a measured interferogram.