公开(公告)号：US09915761B2

公开(公告)日：2018-03-13

申请号：US14834309

申请日：2015-08-24

Applicant: NIKON CORPORATION

Inventor： Hitoshi Ishizawa ,  Shunsuke Niisaka ,  Tsuyoshi Murata

IPC: G02B1/10 ,  G02B1/116 ,  C03C17/00 ,  G02B1/111 ,  G02B1/113 ,  G02B1/118 ,  G02B1/14

CPC classification number: G02B1/116 ,  C03C17/007 ,  C03C2217/45 ,  C03C2217/475 ,  C03C2218/113 ,  G02B1/111 ,  G02B1/113 ,  G02B1/118 ,  G02B1/14 ,  G02B2207/107 ,  G02B2207/109 ,  Y10T428/2495 ,  Y10T428/258

Abstract: An MgF2 optical thin film is formed on an optical surface of a base material. The MgF2 optical thin film includes MgF2 particles and an amorphous silicon oxide-based binder which exists on the surfaces of the MgF2 particles and between the MgF2 particles. Owing to this amorphous silicon oxide-based binder, the optical thin film can have high mechanical strength and high adhesion to the base material, while having excellent environment resistance and a lower refractive index.