| 摘要 |
<P>PROBLEM TO BE SOLVED: To manufacture a prism having high surface accuracy by reducing stress in a dielectric multilayer film, the stress acting on the prism. <P>SOLUTION: A glass member 12 having a triangular prism shape is prepared, and a dielectric multilayer film 11 is formed on a film forming surface 10C of the glass member 12. The film forming surface 10C tends to bend by the stress by the dielectric multilayer film 11, however, the film forming surface 10C is preliminarily curved into a concave or convex surface opposite to the stress of the dielectric multilayer film before the dielectric multilayer film 11 is deposited. The film forming surface 10C is curved with a radius of curvature to give a flat surface of the film forming surface 10C when the dielectric multilayer film 11 is deposited, and hence the film forming surface 10C is corrected to be flat when the dielectric multilayer film 11 is deposited on the film forming surface, so that the dielectric multilayer film 11 does not bend, which prevents problems of aberration or the like. <P>COPYRIGHT: (C)2007,JPO&INPIT |
