Tunable anisotropic photonic crystal channel-drop filter

Abstract

In this numerical study, we present a tunable photonic crystal optical filter designcomposed of anisotropic material. Various tunable optical filters which are composed ofpoint and line defects in a square lattice of dielectric rods, with selective infiltration ofsome of the rods with anisotropic material, are presented. Our numerical simulations withthe finite-difference time-domain (FDTD) technique reveal that defect states originatingfrom the anisotropic material impurities can be effectively tuned. The tunable range of20 nm of the optical channel is obtained. Moreover, we suggest a new tunabletwo-port channel-drop photonic crystal filter based on a Y-splitter and show that, bytuning the characteristics of this structure, total transmission up to 94% and 84%in each output port is achievable. Also, we come to the fact that our proposedstructure, compared to conventional photonic crystal channel-drop filters, hasthe advantages in miniaturizing wavelength-selective filters for WDM systems.