Wave propagation guided by a dielectric slab inserted in a sculptured nematic thin film (SNTF) was studied theoretically. Two types of guided waves can be identified: (i) surface (Dyakonov-Tamm) waves guided by one or both of the two planar interfaces of the dielectric slab and the SNTF, and (ii) waveguide modes in the dielectric waveguide formed by the slab with the SNTF as the cladding. As the thickness of the dielectric slab is increased, the number of waveguide modes increases. If the slab thickness is less than twice the e-folding distance into the dielectric slab, the Dyakonov-Tamm waves propagate coupled to both interfaces; the coupling decreases and eventually vanishes as the slab thickness increases, so that Dyakonov-Tamm waves are guided by the individual dielectric-SNTF interfaces independently. The chosen structure supports the propagation of Dyakonov-Tamm waves in all directions, in contrast to the restricted range of propagation supported by a single SNTF-dielectric interface. Propagation of both Dyakonov-Tamm waves and waveguide modes should occur in practice with negligible attenuation, in contrast to that of surface-plasmon-polariton waves that are guided when the dielectric slab is replaced by a metal slab.
|Original language||English (US)|
|Journal||Physical Review A - Atomic, Molecular, and Optical Physics|
|State||Published - Jan 14 2011|
All Science Journal Classification (ASJC) codes
- Atomic and Molecular Physics, and Optics