Patent ID: 6897962
Filing Date: 2005-05-24
Classification: G01B

Abstract:
1. An interferometer comprising: a beam splitter aligned to receive an input beam and separate the input beam into a first beam and a second beam; a first reflector system positioned to receive the first beam from the beam splitter, the first reflector system directing the first beam back to the beam splitter; a second reflector system positioned to receive the second beam from the beam splitter, the second reflector system directing the second beam back to the beam splitter, wherein the beam splitter forms a first combined beam from the first beam from the first reflector system and the second beam from the second reflector system, the first and second beams in the first combined beam being parallel to each other and walked-off from each other by a distance that depends on relative misalignment of the first and second reflector systems; and a return reflector positioned to return the first combined beam to the beam splitter, whereby the first beam and the second beam from the first combined beam are again separated and then recombined to form a second combined beam in which the first and second beams are collinear, wherein after reflection from the return reflector, the first beam retraces a path parallel to a path the first beam traveled in reaching the return reflector and the second beam retraces a path parallel to a path the second beam traveled in reaching the return reflector.