Patent ID: 8873048

Claim:
A spectrometer assembly adapted for radiation to enter said spectrometer assembly and thereby forming an optical path inside said spectrometer assembly, the spectrometer assembly comprising: a collimator optics for generating a parallel bundle of rays from said radiation entering said spectrometer assembly, a reflective dispersion assembly for dispersing said parallel bundle of rays in a lateral dispersion direction, an Echelle grating for dispersing radiation entering said spectrometer assembly in a main dispersion direction, said main dispersion direction being different than said lateral dispersion direction, wherein said dispersion assembly is arranged along said optical path before said Echelle grating in such a way that said parallel bundle of rays is reflected in the direction of said Echelle grating and wherein said Echelle grating is arranged in such a way that said dispersed radiation is reflected back to said dispersion assembly and passes said dispersion assembly once more, and said collimator optics focuses said reflected, dispersed parallel bundle of rays.