Narrowband transmission filters based on resonant waveguide gratings and conformal dielectric-plasmonic coatings

摘要

Nanostructured filter arrays on image sensors are promising for miniature spectrometers and spectral imagers. In this work, we report on resonant waveguide gratings fabricated by UV nanoimprint lithography and conformal dielectric-plasmonic coatings. Optical measurements in accordance with numerical simulations report on a resonance bandwidth of 20 nm in transmission in the visible range. The impact of cladding thickness and filter lateral size on the resonance properties is investigated with the help of numerical calculations. Finally, it is shown that the proposed geometry based on conformal coatings has a very efficient blocking rate compared to other nanostructured filter approaches.