Modelling of out-of-plane losses in a 2D photonic crystal waveguiding structure fabricated by interference lithography in slow light regime

The results of 3D FDTD calculations of out-of-plane radiation losses in slow light regime for a 2D Silicon-On-Insulator (SOI) Photonic Crystal (PhC) slab are presented. In a 2D PhC slab structure periodicity causes a scattering out of waveguiding modes to the radiating modes. Optical sensors based on 2D PhCs working in slow light regime call for long devices in order to make the path of light propagation longer. At the same time, slowing down the group velocity of light extends signal interaction time with the investigated surroundings. By using a 3D model of an SOI PhC slab we will present the influence of the hole depth and side walls slope of a 2D PhC on the out-of-plane scattering. The possibility of utilising an interference lithograph to fabricate the modelled structure is discussed as well.