Figure 7

The normalized intensity of an LED with and without a multi-layer thin film (MLTF) is denoted on the left axis. The sinus-weighted integral over the intensity difference (grey area)—the so-called cumulated intensity difference—on the right axis indicates that a directionality increase can be achieved up to \(58.4^\circ\). However, the peak of directionality increase is observed between \(35^\circ\) and \(40^\circ\).