Method for producing optical waveguide

A method for producing an optical waveguide that propagates light from a surface of a support to an oblique direction not vertical to the surface, the method for producing an optical waveguide comprising the steps of:

• (1) providing an anti-reflective coating on the support;
• (2) placing a photosensitive resin composition on the anti-reflective coating, and exposing the photosensitive resin composition to a light ray entering from a direction non-vertical to the surface of the support through a photomask for curing the composition;
• and
• (3) removing the unexposed photosensitive resin composition by development,
• wherein the anti-reflective coating is a film formed from a polymerizable composition comprising:
• (a) 100 parts by mass of a reactive silicone compound obtained by polycondensing a diaryl silicate compound of Formula [1] and an alkoxy silicon compound of Formula [2] under presence of an acid or a base:
• (where each of Ar1 and Ar2 is independently a phenyl group optionally substituted with a C1-6 alkyl group;
• Ar3 is a phenyl group having at least one group having a polymerizable double bond or a naphthyl group having at least one group having a polymerizable double bond;
• R1 is a methyl group or an ethyl group;
• R2 is a methyl group, an ethyl group, or a vinylphenyl group;
• and a is 2 or 3), wherein a mixing molar ratio of the diaryl silicate compound of Formula [1] and the alkoxy silicon compound of Formula [2] in the polycondensation reaction is in the range of 1:1 to 1:2;
• and
• (b) 0.1 to 10 parts by mass of an ultraviolet absorber.