Direct nanoimprint as a platform technology for all-inorganic waveguides

We demonstrate the use of nanoimprint lithography using nanoparticle-based inks as a platform technology for low loss, all-inorganic waveguides with refractive indices ranging from 1.7 to 2.3. The all-inorganic character provides superior optical and material stability while low viscosities of the imprint formulations enable significant reductions in imprint time on full-wafer tools relative to polymer/nanoparticle composites. The material sets can be tuned for superior transmission in the blue at RIs of 2.0 and below, relative to TiO2 based materials, while low temperature processing enables compatibility with high index wafers. A few cycles of atomic layer deposition can be used to precisely tune the refractive index of the imprints. Index matching of the imprints to the wafers minimizes effects from the residual layer. Dimensions of the nanostructures can be tuned by conformal cladding.