Nested formation mechanisms of Fano line shape in far-field response of coupled waveguide multilayer structure revealed by analyses of local electric fields

Based on electromagnetic calculations, the formation mechanism of Fano line shape in attenuated total reflection (far-field) spectrum a coupled waveguide multilayer structure is studied detail by tracing back to behaviors local electric fields. The absorptance [Formula: see text] directly related reflectance shown be generated superposition exhibited absorption one layers and Lorentzian another layer. It also that first layer different shapes fields at positions inside These results unveil nested mechanisms hidden resonance thought an example multiple arising from interaction between continua with discrete state.