Index matching layer를 이용한 slow light photonic crystal waveguide로의 결합 효율 향상

초록

This research is about the method to enhance coupling efficiency between the fast light photonic crystal waveguide (PhCW) and the slow light PhCW. Because the slow PhCW has a low group velocity, it provides unique functionalities for integrated photonics, e.g. optical buffers and devices that use optical nonlinear effect. However, an increase of the group index in the slow light PhCW prevents efficient coupling into the slow light PhCW because of increasingly large impedance mismatch. In this study we propose a method to design index matching layer at the interfaces between the fast light PhCW and the slow light PhCW. The design parameters of the optimal index matching layer can be obtained from the antireflection coating theory and the finite-difference time-domain simulations. Furthermore, coupling between strip waveguide and slow light PhCW will be discussed.