DEFORMABLE MIRROR HAVING DISPLACEMENT DETECTING FUNCTION

摘要

PROBLEM TO BE SOLVED: To provide a deformable mirror by which the displacement of the reflection surface can be detected so as to control the form of the reflection surface highly precisely. SOLUTION: The deformable mirror has a flexible thin film 8 having a reflection face which deforms by electrostatic attraction and having an upper electrode and has a control electrode 2 disposed facing the flexible thin film 8. The capacitance between the upper electrode 6 and the control electrode 2 of the deformable mirror is detected to calculate the displacement of the reflection surface.