US Patent 10967940 UV LED waveguide system with scattering for anti-fouling

The invention provides a waveguide element (1000) comprising a first face (1001) and a second face (1002) with radiation transmissive material (1005) configured between the first face (1001) and the second face (1002), wherein the radiation transmissive material (1005) is transmissive for UV radiation, wherein the radiation transmissive material (1005) is a matrix material for a phase (1010) of another composition than the radiation transmissive material (1005), wherein the phase (1010) is available in the matrix as regions (1110) with the regions (1110) having mean particle radii (r1) selected from the range of 50-1500 nm and having an average region concentration selected from the range of 1*104-1.5*108/mm3 of the radiation transmissive material (1005).