| 摘要 |
PROBLEM TO BE SOLVED: To enhance the optical characteristics of an optical waveguide by forming a polymer film on the surface of a substrate and pressing a smooth hot plate on the polymer film to smoothen the surface of the polymer film. SOLUTION: A polymer film 2 is formed on the surface of a polymer substrate 1 and the surface of the polymer film 2 is smoothened by pressing a smooth hot plate on the polymer film 2 to obtain the objective optical polymer substrate. Various polymers may be used as the polymer of the polymer substrate 1. When a polymeric waveguide is formed on the optical polymer substrate, the heat resistance, coefficient of thermal expansion and elastic modulus of the substrate material are preferably made equal to those of the optical waveguide materials. A polyimide film is formed on a polyimide template, a hot plate having a prescribed surface roughness heated to a temperature close to the softening point of the polyamide film is pressed on the surface of the polyimide film to smoothen the polyimide film and an optical waveguide is produced on the smoothened polyimide film. Since the resulting optical substrate has a small average surface roughness, the produced polymeric optical waveguide has small polarization dependency and small light loss. |
