An efficient hybrid plasmonic dichroic splitter based on subwavelength periodic metallic nanoslits

An efficient plasmonic dichroic splitter based on periodic metallic nanoslits milled in the metal-dielectric-Si hybrid plasmonic waveguide is proposed and investigated. The backside incident photons illuminated on the dichroic splitting structure are coupled and launched into the hybrid plasmonic modes propagating to the left- or right-side depending on the wavelength. Proof-of-principle demonstrations show that the good coupling and splitting performances with coupling efficiency 0.5 and high splitting ratios 26.4 dB at wavelength 1310 nm (right:left power contrast), and 0.46 and 21.7 dB at wavelength 1550 nm (left:right power contrast) are achieved, respectively. The operation principle is clarified and the performance is discussed.