Measuring device by laser interferometry.

摘要

Device for laser interferometric measurement of the variation of the distance separating a stationary point and a moving point in space each having a reflecting target (8, 9). The device comprises a source (2) of a coherent light beam (1), a separating surface (3) arranged on the path (1) of the beam for dividing the latter into a through beam (4) and a diverted beam (5) and comprising a surface for reflecting the diverted beam (5) in a parallel direction to the through beam (4), a tracking optical device (7) receiving, firstly, at the input the two parallel beams (4 and 5) and pointing them while holding them parallel in the direction of the two targets (8, 9) so that one of the beams (4, 5) is continually pointed toward the respective targets (8) and, secondly, the parallel beams reflected by the same targets (8, 9) in order to point them, while holding them parallel, towards the separating (3) and reflecting (6) surfaces.