Laminated structures for optical waveguides, and optical waveguides

Abstract

This invention relates to a multilayer for optical waveguides, comprising a core layer and a cladding layer. The core layer is composed of a first polyimide having structural units shown in general formula (1), and the cladding layer is composed of a second polyimide having structural units shown in general formula (1). When the fluorine substitution rate of the first polyimide is set as fcore and the fluorine substitution rate of the second polyimide is set as fclad, the following equation is satisfied: fclad > fcore.