Angle-tolerant hybrid plasmonic blue filter with polarization-insensitivity and high transmission

The optical blue filter with the suitable bandwidth, high transmittance and large acceptance angle is usually regarded as a critical optical component for a variety of applications. Here, we propose a polarization-insensitive angle-tolerant hybrid plasmonic blue filter incorporating two-dimensional aluminum (Al) nanodisks on the top of planar waveguide. The proposed plasmonic filter works via hybridization of surface plasmon polariton (SPP) mode, the localized Fabry-Perot resonance and waveguide mode, thus enables high peak transmittance up to 70% with the bandwidth of 30 nm and large acceptance angle up to 20°.