Flat Band Slow Light Performance in Dual-Slot Silicon-on-Insulator Based Photonic Crystal Waveguide

Abstract

The photonic band structure and slow light performance in dual-slot photonic crystal waveguide based on silicon-on-insulator (SOI) substrate are studied by using three-dimensional (3D) plane wave expansion method. The numerical results show that both the position and the width of the slots have significant effect on photonic band structure. The guided mode edge and the photonic band gap increases with the increasing of the two slots' widths. When slots move close to the boundary of the waveguide, a flat band of slow light appears. The slow light property has also been discussed by modifying the radius of the two rows of air holes nearest to the dual-slot waveguide. The negligible dispersion bandwidths ranging from 6.70 to 25.70 nm for group indices from 62 to 20 are obtained, respectively. The numerical results show that the proposal structure has potential application in optical buffer.