The present invention provides a wavelength multiplexer/demultiplexer comprising a plurality of regions of optically permissive material. The plurality of regions are disposed adjacent one another in a side by side relationship in order to define a stratified body. The materials in adjacent regions have differing indexes of refraction. The stratified body has a first surface and a second surface that are positioned in a non-parallel relationship with respect to one another. The first surface is a light-receiving surface, and the second surface is a light-exiting surface.