Wavelength converting element

A wavelength converting element (110) comprising a polymeric material having a polymeric backbone, the polymeric material comprising a wavelength converting moiety, wherein the wavelength converting moiety is adapted to convert light of a first wavelength to light of a second wavelength, and wherein the wavelength converting moiety is covalently attached to the polymer backbone and/or covalently incorporated into the polymer backbone. The stability and lifetime of wavelength converting molecules comprised in a polymeric material may be improved by covalently attaching the wavelength converting moieties to the polymeric material.