Method for estimating absolute distance of tracking laser interferometer and tracking laser interferometer

摘要

A method for estimating an absolute distance between a tracking laser interferometer and a retroreflector is provided. The tracking laser interferometer includes the retroreflector for reflecting and returning an incident measurement light in an incident direction and a two-axis rotating mechanism for rotationally moving in an exit direction of the measurement light so that optical axes of the measurement light and return light are collimated.