A distributed feedback (DFB) waveguide cavity with erbium-tris(8- hydroxyquinoline) has been fabricated by X-ray interference lithography in a laboratory-scale apparatus. The DFB cavity consists of a large area (∼8mm2) one-dimensional grating of polymethylmethacrylate on Si (1 0 0). Structural, morphological and optical properties of the device have been studied. On-grating narrowing of the photoluminescence emission has been observed for the 492 nm grating period in correspondence to the 4f4f Er band peak (at 1530 nm), indicating the possibility of optical gain for applications in the telecommunications. © 2010 Elsevier B.V.