Abstract: A risk of occurrence of folds, cracks, peeling, and the like in a heater electrode pattern is avoided beforehand by forming a thin-film heater electrode pattern on a polymer optical waveguide with good adhesiveness, and minimizing surface damage of the polymer optical waveguide due to an electrode forming process. According to an electrode forming method for a polymer optical waveguide, after the surface of the polymer optical waveguide is subjected to activation processing, a heater electrode film is formed on the entire surface thereof. A resist is then applied onto the heater electrode film, to form a resist pattern by photolithographic processing in which a heater electrode is patterned. The resist pattern is etched to form a heater electrode pattern, and then remaining resist on the heater electrode pattern is removed.

Abstract: An optical multiplexer/demultiplexer is used in a wavelength division multiplexing. An optical energy transmission body has N side faces, where N is equal to or larger than three. A first predetermined one of the N side faces directs a single beam of radiant energy, at a predetermined angle, into or out of the body for carrying out the demultiplexing or multiplexing operation. The single beam contains M preselected wavelengths, where M is equal to or smaller than N-1. A plurality of beam passing means are associated in a one-to-one correspondence with (M-1) of the N side faces. The beams which pass through the M-1 side faces contain a corresponding one of M wavelengths and reflect a beam containing at least one of the M wavelengths, other than the corresponding wavelength. Another of the N side faces passes a beam which is finally reflected by the plurality of beam passing means.