| 摘要 |
PROBLEM TO BE SOLVED: To provide a diffraction optical element that can be easily manufactured while maintaining preferable diffraction efficiency. SOLUTION: The diffraction optical element 1 consists of resins of different materials and has a layered structure having a second diffraction element 20 interposed and joined between a first diffraction element 10 and a third diffraction element 30. Grating grooves 2 formed on the first diffraction element 10 and grating grooves 3 formed on the second diffraction element 20 are tightly joined to each other to form a first diffraction optical face 6 on the joined face of the first diffraction element 10 and the second diffraction element 20, grating grooves 4 formed on the second diffraction element 20 and grating grooves 5 formed on the third diffraction element 30 are tightly joined to each other to form a second diffraction optical face 7 on the joined face of the second diffraction element 20 and the third diffraction element 30, and both of the non-joined face of the first diffraction element 10 and the non-joined face of the third diffraction element 30 are composed of continuous faces. COPYRIGHT: (C)2008,JPO&INPIT |
