Resonant splitting in periodic T-shape photonic waveguides
  Resonant splitting phenomena of photons in periodic T-shape waveguide structure are investigated by the Green's function method. It is found that, except for the (n-1)-fold resonant splitting in the low frequency region, (n-2)-fold resonant splitting occurs in the high frequency region of the transmission spectra. The (n-2)-fold resonant splitting peaks are induced by the high quasi-bound states where the photons are mainly localized in the constrictions rather than in the stubs. To this kind of quasi-bound state, the stub acts as a potential barrier rather than a well, which is the inverse of the case of the low quasi-bound states corresponding to the (n-1)-fold splitting peaks. These resonant peaks can be modulated by adjusting the periodic number and geometry of the waveguide structures. 
Wenjin Yin, Kaike Yang, Yuee Xie, Tao Ouyang and Yuanping Chen
cond-mat.mes-hall cond-mat.mtrl-sci physics.optics