A multi-layer structure is provided. The multi-layer structure includes: a waveguide including a light coupling arrangement, wherein the light coupling arrangement is substantially non-wavelength selective; at least one light source disposed above the waveguide; and at least one photo detector disposed above the waveguide; wherein the at least one light source, the at least one photo detector and the waveguide include organic material, and wherein the waveguide, the light coupling arrangement, the at least one light source and the at least one photo detector are monolithically integrated.