Phase resonances in multilayer metal-dielectric compound gratings are numerically modeled and described. Additional grating layers allow for more complex types of phase resonances in which light travels in different, circuitous routes through the structure. It is shown that phase resonances produce highly enhanced fields, have a very narrow bandwidth, are Fano resonances with asymmetric line shapes of their reflectance, and produce a complete inversion in the transmittivity and opacity of low loss structures. Several multigrating structures are numerically modeled that show the addition of more complicated phase resonances as more layers are added to the structure. The dispersion curves of the multiple bands of phase resonances are predicted using an analytical approach and numerical modeling. Applications of the resonance effects are described for optical filters.

• Received 22 January 2013

DOI:https://doi.org/10.1103/PhysRevA.87.053847