At one side of a substrate, a vertical diffraction grating is formed integrated with the substrate, at the other side of the substrate, one pair or more of fibers are disposed through which either light goes from the vertical diffraction grating or light comes into the vertical diffraction grating, and a lens member is disposed between the fibers and the vertical diffraction grating. At the other side of the substrate, positioning means which positions a plurality of fibers is formed integrated with the substrate, and a space between the vertical diffraction grating and the fibers constitutes a waveguide.