Figure 3: (a) The local diffraction intensity of the negative first order at the exit surface of the MLL with a section depth of 1.5 and 10 μm in the normal incidence and tilted geometries. The dashed lines are calculated by the geometrical theory (4) in the cases of thick section (black) and thin section (red), assuming a normal incidence. (b) Efficiency of the negative first order as a function of the tilting angle and the section depth.