The study of the dependence of surface mode dispersion on the termination of multilayer stacks reveals interesting features. For stratified media with high-refractive-index contrasts, surface modes can shift across several bandgaps if the thickness of the final layer is changed. The distance to the photonic band edge influences the decay length of the mode inside the multilayer stack. In the middle of the bandgap, the electromagnetic energy is concentrated in the final layer of the crystal, while near bandgap edges the decay length extends over several periods. Additional evidence suggests that surface modes behave like guided modes that can couple with the extended Bloch modes and give rise to evanescent field profiles oscillating along several periods.
© 2008 Optical Society of America
Optics at Surfaces
Original Manuscript: April 21, 2008
Revised Manuscript: August 19, 2008
Manuscript Accepted: August 29, 2008
Published: September 30, 2008
Cédric Vandenbem, "Electromagnetic surface waves of multilayer stacks: coupling between guided modes and Bloch modes," Opt. Lett. 33, 2260-2262 (2008)