Optical characteristics of Al/Si structure and Ag/Al2O3/Ag plasmonic thermal emitter with square and hexagonal lattice

Optical emission spectra of the tri-layer Ag/Al₂O₃/Ag plasmonic thermal emitter with square and hexagonal lattice are consistent with the extraordinary transmission through Ag/Si structure with similar lattices. The plasmonic thermal emitter with hexagonal periodic lattice emits only one strong (1,0)Ag/Al₂O₃ peak, tends to suppress the (1,0)Ag/air and (1,1)Ag/Al₂O₃ SP modes, whereas a similar plasmonic thermal emitter with square periodic lattice emits two strong (1,0) and (1,1)Ag/Al₂O₃ peaks, their relative intensities follow the blackbody radiation law. Its fits well to the transmission spectra of the Ag/Si structure with square and hexagonal lattice, the (1,0)Ag/air and high order Ag/Si Rayleigh-wood´s anomaly, the (1,0)Ag/air and (2,0), (2,1)Ag/Si SP modes were excited when the holes cover more than 12.6%or 14.5%of the total area of the Ag film, respectively.