We report on a method of creating spectrally selective diffractive optical elements based on resonantly reflecting mirrors made of semiconductor structures with 2D Wannier–Mott excitons. This method employs strong dependence of resonant reflection coefficient on the inhomogeneous broadening determined by exciton scattering on the quantum-well structural defects. Realization of the proposed method of addressable control of the excitonic resonance inhomogeneous width includes two stages. At the first stage the substrate surface is exposed to an ion beam with intensity relief corresponding to the desired diffractive optical element pattern. Then the structure with quantum wells is being grown on the exposed substrate by molecular beam epitaxy. In this article we present a spectroscopic study of structures with InGaAs/GaAs quantum wells grown on a GaAs substrate patterned with arrays of periodical parallel lines by a focused Ga+ ion beam. These structures combine properties of the diffraction grating with spectral selectivity of 2D-exciton resonance.