Multilayer arrow channel waveguide for evanescent field enhancement in low–index media

A multilayer antiresonance reflecting optical waveguide (ARROW) channel waveguide geometry, believed to be novel, is proposed for enhancing the evanescent field in low–index materials. The finitedifference method is used in the analysis of the structure. The fraction of the fundamental TE–like–mode power in the low–index material (air) is used as a measure of the evanescent field enhancement. The calculated results suggest that the evanescent field of the fundamental TE–like mode can be significantly increased in air while the low modal loss that characterizes the leaky nature of the structure is maintained. The results also suggest that a semivectorial approach to this problem is adequate for analysis of the proposed waveguide structure.