Interferometer for length measurement

Not Applicable A measurement interferometer () having a frame structure (), a laser source (), a detector (), a beam splitter (), a reference retroreflector (), a reference holder () and a test retroreflector (). The reference rertoreflector () and beam splitter () are disposed in fixed relation to the reference holder () to constitute a splitter-holder assembly (). The test retroreflector () and the splitter-holder assembly () are movable relative to each other and both are movably mounted on the fine structure (). Preferably, the test retroreflector () is situated between the reference holder () and the beam splitter (). In a particular embodiment the beam splitter () is connected to the reference holder () by a carbon composite rod (), and the test retroreflector () is mounted on a probe () made from a carbon composite. In one embodiment, the reference retroreflector () is integral with the beam splitter (). There may be a vibration-dampening member such as a spring () between the splitter-holder assembly () and the frame structure ().