A low-dimensional plasmon-light emitter for converting an inputted electric energy luminescence with an arbitrary energy over a broad range. The emitter has a low-dimensional conductive structure incorporated inside or in a surface layer of a semiconductor or dielectric. A periodic nanostructure is incorporated in the vicinity of or inside the low-dimensional conductive structure. The low-dimensional conductive structure may be a quantum well formed inside a semiconductor or dielectric, a space-charge layer formed on a surface or heterojunction of a semiconductor or dielectric, or a surface or interface electronic band with high carrier density formed on a surface or heterojunction of a semiconductor or dielectric. The periodic nanostructure is selected from a periodic structure formed by vapor-deposition or etching of fine metallic wires, a periodic structure of a film formed on surfaces with atomic steps, or a periodic structure self-organized during epitaxial growth or polymerization of an organic molecule or polymer.