Low-dispersion reflector

A retro-reflector comprising:

• a front boundary surface configured for entry of measuring light into the retro-reflector and
• a back boundary surface configured for reflecting the measuring light as reflected measuring light,
• wherein:
• the front boundary surface and the back boundary surface are arranged on opposite sides of the retro-reflector, and
• an optical axis is defined by the arrangement of the front boundary surface and/or the back boundary surface of the retro-reflector, wherein an incidence angle of the measuring light relative to the optical axis is equal to an exit angle of the reflected measuring light relative to the optical axis,
• a first optical element comprising the front boundary surface, and
• a second optical element comprising the back boundary surface,
• wherein:
• the front boundary surface and the back boundary surface are of curved shape,
• the first optical element and the second optical element are of different shape and/or size,
• the retro-reflector comprises an intermediate member arranged between the first optical element and the second optical element,
• the first optical element is connected to the second optical element by means of the intermediate member, and
• the retro-reflector is configured so that the measuring light entering into the retro-reflector at the front boundary surface is focused at the back boundary surface.