INTERFEROMETRIC CYCLIC ERROR COMPENSATION

摘要

The invention features an interferometry method including: directing two beams derived from a common source along different paths producing a first output beam I1 derived from a first portion of each of the two beams: producing a second output beam I2 derived from a second portion of each of the two beams and calculating a product 320 of a first signal S1 derived from the first output beam and a second signal S2 derived from the second output beam.