Patent ID: 7542149

Claim:
An optical assembly of an interferometer, comprising: a beam splitter for dividing the beams emitted by a radiation source into at least one measuring and one reference beam; at least one measuring and one reference mirror, arranged along at least two measuring axes, on which the measuring and the reference beams impinge, respectively, wherein respectively at least one of the mirrors is displaceable along a respective one of the at least two measuring axes; a beam deflector, as well as a retro-reflector, wherein the measuring and the reference beams reflected at the measuring and the reference mirrors are received by both the beam deflector and the retro-reflector and are guided by the beam deflector and the retro-reflector at least a second time in a direction toward the measuring and the reference mirrors; an axis splitter, arranged between the beam deflector and the retro-reflector, which divides the measuring and the reference beams so as to be parallel to the at least two measuring axes, wherein the axis splitter comprises at least one plane-parallel plate.