1. A light emitting device comprising:a light source having a light exit surface:
a wavelength converter configured to convert light from a first wavelength to a second wavelength, said wavelength converter having a light exit surface and a light entrance surface which extend in an angle different from zero to one another;
a heat sink; and
an optical coupling element arranged in contact with said wavelength converter, and in thermal connection with said heat sink;
wherein said optical coupling element is selected to have a refractive index in the range of 1.1-1.6, and lower than a refractive index of said wavelength converter, and
said heat sink is thermally connected to said wavelength converter through said optical coupling element.