We find the conditions for the existence of trapped modes in planar periodic particle arrays. Confined excitations of TE and TM symmetry are observed in symmetric environments, originating in lattice resonances that are signalled by the onset of new diffraction beams. This mechanism of mode formation is shown to be inhibited by the presence of a dielectric interface in an asymmetric configurati...

background : this study was set to determine the optimal technique of breast cancer with supraclavicular fossa irradiation. methods : three techniques was compared in this study. techniques were two point symmetric (2p-sym), two point asymmetric (2p-asym) and single point (sp). in 2p-sym all of beams were symmetric, in 2p-asym tangential beams were symmetric and supra was asymmetric, in sp all ...

Loss compensation via inserting gain is of fundamental importance in different branches photonics, nanoplasmonics, and metamaterial science. This effect has found an impressive implementation the parity-time symmetric (PT-symmetric) structures possessing balanced distribution loss gain. In this work, we generalize phenomenon to asymmetric systems demonstrating coupled multi-mode loss-gain diele...

The resonant photon emission following the excitation of a highly symmetric system to core-excited electronic states is discussed within a time-dependent formulation. Two types of vibrational modes—localizing modes and symmetry breaking but nonlocalizing modes—are considered, named according to their impact on dynamical symmetry breaking and localization accompanying the process. The decay rate...