| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide an inorganic birefringent element which has an improved moisture dependence and, moreover, has satisfactory optical characteristics. <P>SOLUTION: The birefringent element 1 is prepared by stacking monolayer or multilayers of inorganic oblique deposition films 13A to 13D made of dielectric material on the surface of a light transmitting base 11. The inorganic oblique deposition films 13A to 13D have a film structure composed of: a large number of columnar structures extended in an oblique direction with respect to the surface of the light transmitting base 11; and a large number of voids which are formed among the large number of columnar structures and are extended in the direction substantially equal to that of the columnar structures, wherein the average cross-section area of the voids in the inorganic oblique deposition film 13D located on at least the uppermost layer is 10 to 7,500 nm<SP>2</SP>. <P>COPYRIGHT: (C)2007,JPO&INPIT |
