Monolithic displacement measuring interferometer with spatially separated but substantially equivalent optical pathways and optional dual beam outputs

Abstract

An interferometer and corresponding system are provided having several aspects. In a first aspect, there is provided an interferometer adapted to receive separate first and second beams fand ftherein, the interferometer comprising substantially equivalent and separate first and second optical pathways for the first and second beams fand f. In a second aspect, there is provided an interferometer adapted to receive as separate inputs therein first and second beams fand f, where such beams are not mixed or combined until just prior to being output by the interferometer. In a third aspect, an interferometer is provided having one or more beam blockers for intercepting extraneous or undesired light, and keeping such light from contaminating or interfering with separate beams fand f.