Radii changing effect on the coupling efficiency between a silica waveguide and a planar photonic crystal

摘要

In this paper, we designed different structures for PPC tapered waveguide to enhance the coupling between silica waveguide (SWG) and planar photonic crystal (PPC). The designed structures are based on changing the radii of the inner PPC tapered waveguide's crystals before and after adding extra defects. We found that above 88% transmission efficiency is possible by using extra defects followed by radii changes. We also found that changing the operating wavelength from 1.55 μm to 1.558 μm increases the transmission efficiency to 90% since the field is more confined at the later wavelength.