Tailored chromatic diffraction efficiency of double-layer single-relief blazed gratings.

"Wavelength selectivity" is an important intrinsic property of diffractive optical elements that offers significant application potential. Here, we focus on tailored wavelength selectivity, the controlled efficiency distribution into different specific diffraction orders for selected wavelengths or wavelength ranges from UV to IR using interlaced double-layer single-relief blazed gratings composed of two materials. Dispersion characteristics of inorganic glasses, layer materials, polymers, nanocomposites, and high-index liquids are taken into account to investigate the impact of especially intersecting or partially overlapping dispersion curves on diffraction efficiency in different orders, providing a guideline for material choice depending on the required optical performance. By selecting appropriate combinations of materials and adjusting the grating depth, a wide variety of small or large wavelength ranges can be assigned to different diffraction orders with high efficiency that can be beneficially applied to wavelength selective functions in optical systems also including imaging or broadband lighting applications.