Schematics of wave-scattering from (a) the nano-transmission grating whose period is 100 nm and (b) the square-wave grating whose period is 400 um. Calculated \(n\)-th-order diffraction angles of the matter-wave whose de Broglie wavelength is 136 pm over certain ranges of incidence angles from each grating are shown in (c) and (d), respectively. Dashed lines(solid lines) indicate the diffraction angles of negative orders (positive and specular orders).