Two-dimensional crystalline micro-tiles are prepared from a small organic hexaphenylsilole (HPS) compound by a self-assembly process. Characteristics of the single micro-tiles indicate that they can serve as active directional optical waveguides. When the excitation point is at one end of a micro-tile, waveguided light is found at the opposite edge and at the nearest parts of the neighboring edges of the micro-tiles, but emission at the diagonal positions is weak or absent (see image).