INTERFEROMETER

摘要

PROBLEM TO BE SOLVED: To provide an interferometer in which fluctuation in the optical path length within interferometer can be eliminated over a long time. SOLUTION: A Michelson interferometer comprises a beam splitter 10 and a movable mirror assembly 11. The mirror 11 is fixed to a back plate 13 by means of three piezoelectric actuators 12. A movable mirror element 14 is fixed to the back plate 13 in the path of a light passing through the beam splitter 10. A rigid structure where the mirror 11 is fixed to the beam splitter 10 through the back plate 13 and actuator 12 realizes a time invariant structure.