METHOD FOR FORMING PERIODICAL PLANE AND OPTICAL ELEMENT OBTAINED BY THE METHOD AND METHOD FOR CUTTING OPTICAL ELEMENT

摘要

PROBLEM TO BE SOLVED: To provide a method for manufacturing an optical element having a surface which can be used as an optical reflecting surface by utilizing anisotropic etching of silicon with a single process of anisotropic etching with the efficiency and in large quantities. SOLUTION: The (100) plane of a single crystal silicon substrate is subjected to the anisotropic etching to form a periodical face composed of the (111) planes 24'. The <111> direction is defined as the orientation flat direction 15, and the etching mask 14 used has a periodical recess pattern having edges 12 having an angle larger than 1 deg. and smaller than 44 deg. to the direction of the (111) plane predicted from the orientation flat direction.