Spectrometer

A compact spectrometer comprising:

• a reflection grating (1);
• and
• at least one prism (2) in combination with the at least one grating (1),
• wherein:
• beginning of total reflection is provided in the at least one prism (2) in order to achieve the compact spectrometer and a splitting of incident and reflected rays of the reflection grating (1), and
• the at least one prism (2) is positioned in such a manner that a light beam passes through the at least one prism (2) twice, and
• wherein at least one of:
• characteristics of the spectrometer are linear in the circular wave number,
• the spectrometer compensates a dispersion-induced non-linear relationship between wavelength and focal point of a confocal chromatic measurement system such that overall characteristics of the spectrometer become linear in the object distance, or
• the spectrometer characteristics are linear in the wavelength.