Polarization-independent plasmon-induced transparency for plasmonic sensing

We design a three-dimensional structure consisting of cross-slit metallic photonic crystals and dielectric photonic crystals embedded in a background material to achieve electromagnetically induced transparency for TE/TM polarization modes. Numerical simulation demonstrates that the mechanism of this phenomenon is based on the coupling effect between the excited surface plasmonic mode and waveguide mode supported by metallic and dielectric photonic crystals, respectively. In particular, one of the transmission dips of the system is very sensitive to the background material, where the sensitivity (nm/RIU) of the system is more than 700 nm/RIU. Meanwhile, polarization-independent transparency of the structure makes our system possess great potential for achieving high-performance sensors.