Coupling of surface plasmons between two silver films in a plasmonic thermal emitter

摘要

The emission spectra of Ag/SiO_2/Ag trilayer plasmonic thermal emitters with various SiO_2 thicknesses were investigated. By analyzing the relationship between emission peaks and thicknesses of SiO_2, the coupling of surface plasmons between two silver films in a plasmonic thermal emitter is demonstrated and the coupling length is determined as well. Furthermore, the dispersion relation of plasmonic thermal emitter is detected by measuring the reflection spectra with various incident angles. This confirms that the main mechanism involved in the emission of a plasmonic thermal emitter is due to the excitation of surface plasmons.