| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a reflection layer for improving durability to assure higher reflection efficiency by eliminating difference in lattice constant, when a first Bragg reflection film and a second Bragg reflection film are laminated. <P>SOLUTION: The reflection layer comprises the first Bragg reflection film 21 having a first refractive index, a lattice distortion buffering film 22 formed on the first Bragg reflection film 21, and a second Bragg reflection film 23 formed on the lattice distortion buffering film 22, and having a second refractive index. The lattice distortion buffering film 22 changes its refractive index in the approximating direction to the second refractive index from the first refractive index as it becomes nearer the second Bragg reflection film 22 from the first Bragg reflection film 21. <P>COPYRIGHT: (C)2008,JPO&INPIT |
