Stability of the homogeneous mode in the metamaterial regime with structural disorder

This research considers the stability of the epsilon-near-zero homogeneous mode in the metamaterial composed of dielectric rods. The homogeneous mode is shown to be tolerant to modification of the geometrical shape of metamaterial boundaries as well as to introduction of internal boundaries associated with super-wavelength voids inside the structure. Additionally, we study the influence of structural disorder, namely, the deviation of the rod position from the lattice sites, which is the inherent feature of any real structure. We investigate the influence of the disorder degree on homogeneous mode stability. The closer parameters of the structure are to the boundary of the "photonic crystal-metamaterial" transition, the less stable the epsilon-near-zero homogeneous mode is. The homogeneous mode collapses at a fixed frequency; however, there is a range of disorder degree at which the homogeneous mode is still observed but at a lower frequency. While the change in frequency is weak, the epsilon-near-zero homogeneous mode is robust against the introduction of structural disorder. (c) 2023 Optica Publishing Group