Spectrometer with two-dimensional spectrum

An optical component, comprising:

• a freeform surface embodied to optimize imaging error caused area occupied by selected images of an entrance slit of a spectrometer of different wavelengths in an image plane over a selected spectral region of a two-dimensional echelle spectrum, wherein the optical component is adapted for retrofitting a spectrometer arrangement, the spectrometer arrangement including:
• a first dispersing element embodied to spectrally separate radiation in a main dispersion direction to yield dispersed, monochromatic beams, wherein the first dispersing element is an echelle grating;
• an imaging optics embodied to image the radiation entering into the spectrometer arrangement through the entrance slit along a beam path in the image plane for producing a two-dimensional echelle spectrum;
• a detector array having a two-dimensional arrangement of a plurality of detector elements in the image plane;
• a second dispersing element embodied for order separation using spectral separation of the radiation in a cross dispersion direction, thereby forming an angle with the main dispersion direction of the first dispersing element such that a two-dimensional spectrum is producible;
• and
• a reflector, a refractor, a lens array and/or other optical element arranged in the beam path at a location where the dispersed, monochromatic beams are separated from one another,
• wherein the freeform surface is included on the reflector, the refractor, the lens array and/or the other optical element,
• wherein the freeform surface is arranged at a position where relative beam overlapping is less than on a camera mirror element, wherein the relative beam overlapping at the position in the beam path is a reciprocal arithmetic ratio between a beam cross-sectional area of a selected monochromatic beam at the position and an area portion thereof, which is likewise occupied by a second monochromatic beam.