Figure 3.

Intensity beam profile of the UV emanating from the high-power LEDs. The top panels represent colour-coded beam intensities over a two-dimensional screening, with the schematic representation of the LED arrangement at the bottom right. The middle and bottom panels are transversal views. (a) The measured UV was 268.8 nm, with the two blocks arrangement within the LED resulting in two major peaks. (b) The measured UV was 283.7 nm, with an elongated and homogeneous distribution of the beam. UV-illuminated crystals are represented as insets.