Plasmonic induced reflection based on Al2O3 nanoslit side coupled with silicon nanodisk resonator

plasmonic induced reflection (PIR) effect has potential applications in many nanophotonics devices, Such as slow light, absorber and filter. To realize plasmonic induced interference, in this paper, we present PIR effect in a periodic subwavelength array of nanoslit side-coupled to nanodisk resonator. Both finite-difference time-domain (FDTD) and coupled-mode theory (CMT) method indicate that the destructive interference between the bright mode resonator (nanosilt) and dark mode resonator (nanodisk) leads to PIR effect. Double-band absorption with maximum absorbance up to 96% and 90% is achieved 1440 nm and 1661 nm, respectively. The effect of structural parameters on reflection and the field distribution are also studied in detail. Moreover, multiple PIR effect can be realized by introducing more dark mode resonators. The results will pave the way towards the design of double band PIR, which may have potential application in slow light technology, plasmonic modulator, plasmonic filter and multiband plasmonic absorbers.