Significantly enhanced coupling efficiency in 2D photonic crystal waveguides by using cabin-side-like tapered structures at two terminals

Abstract

We report that using a cabin-side-like tapered structure, containing only one pair of defects, can markedly enhance the coupling efficiency at the entrance and exit terminals of planar photonic crystal waveguides (PPCWGs). The PPCWGs are composed of circular dielectric rods set in 2D triangular lattices. By means of simulations, we find that the transmission efficiency reaches up to 90%. Moreover, the suggested structures possess other advantages, such as the shortness of the taper, the ease of fabrication, and its low cost. It is anticipated that the proposed structures might be feasibly be applicable to the integrated optical circuits compatibility.