Multiplexer-demultiplexer for integrated optic circuit

Claim 1

A substantially dry method for forming an optical multiplexing-demultiplexing device, said device comprising a branched optical waveguide formed in a laminated matrix, said waveguide comprising a branching region for dividing a transmitting optical path into an input optical path and an output optical path, said branching region comprising a volume grating, said method comprising the steps of: (A) providing a substantially dry photohardenable film having first and second surfaces, with a support removably adhered to the first surface; (B) exposing the film to form the optical waveguide comprising a transmitting path, an input path, an output path, and a branching region; (C) exposing the film to form a holographic diffraction grating in the branching region of the optical waveguide; (D) laminating a first surface of a first substantially dry photohardenable layer to the film second surface, with a support removably adhered to a second surface of the first layer; (E) removing the support form the film first surface; (F) laminating a first surface of a second substantially dry photohardenable layer to the film first surface, with a support removably adhered to a second surface of the second layer; and (G) hardening the layers and film forming a hardened matrix, substantially fixing the indices of refracting of the layers and the film, and forming at least one buried waveguide; said steps being carried out in the order indicated except that step (C) may be carried out after step (A), step (B), step (D), step (E), step (F), or step (G).