RESIN COMPOSITION FOR FORMING OPTICAL WAVEGUIDE, RESIN FILM FOR FORMING OPTICAL WAVEGUIDE, AND OPTICAL WAVEGUIDE USING SAME

摘要

Provided are: a resin composition for an optical waveguide, the resin composition being soluble in an alkaline aqueous solution, being capable of patterning required by alkali developing, and having excellent light propagation loss at wavelengths of 830-850 nm; a resin film for an optical waveguide; and an optical waveguide using the same. This resin composition for an optical waveguide contains (A) a polymer, (B) a polymerizable compound, and (C) a polymerization initiator, and the relationship between the refractive index (A) of the resin composition when heat-cured after being irradiated with ultraviolet rays and the refractive index (B) of the resin composition when heat-cured after being irradiated with ultraviolet rays and then immersed in an alkali developing solution being A > B. An optical waveguide fabricated by alkali development using this resin composition has a surface region having a lower refractive index than a center part of a core pattern in at least a portion of the periphery of the core pattern for forming a core layer. Effects are therefore obtained whereby leakage into a cladding layer of light propagated through the core layer is suppressed, and light propagation loss can be reduced.