| 摘要 |
PROBLEM TO BE SOLVED: To obtain thin film laminated optical parts which have a preventing effect against peeling and which can be easily produced at a low cost by applying a low thermal expansion film on the opposite face of an optically function film to the face where the optically function film is in contact with a substrate in such a manner that the coefft. of thermal expansion of the low thermal expansion film is smaller than that of the optically functional film. SOLUTION: The laminated optical part consists of a substrate 2, an optically function film 35 which is comprised of a clad 32 and a core 34 formed on the substrate 2 and has a larger coefft. of thermal expansion than that of the substrate 2, and a low thermal expansion film 60 which is formed on the opposite face of the optically functional film 35 to the face in contact with the substrate 2 and has smaller coefft. of thermal expansion than that of the optically function film 35. The substrate 2 is a silicon substrate, and the optically function film 35 is an optical waveguide made of a polyimide film. The material used for the low thermal expansion film 60 is required to satisfy the conditions that it has a smaller coefft. of thermal expansion than that of the optically functional film 35, it does not change the optical characteristics of the optically function film 35 and it can be deposited on the surface of the optically functional film 35 and it is more flexible than the silicon substrate 2. To satisfy the conditions as described above, fluorinated polyimide is preferably used as the material for the low thermal expansion film 60. |
