Compact and Tunable Slow and Fast Light Device Based on Two Coupled Dissimilar Optical Nanowires

We propose a novel and compact all-optical device for tunable slow and fast light propagation in parallel coupled structures consisting of two dissimilar optical nanowires. Advancement/delay tunability is achieved by varying the spacing between two nanowires. We develop a simplified analytical model to describe the dependence of achievable time advancement/delay and pulse broadening on the diameter of optical nanowires and it is indicated that this model agrees well with numerical results. Simulation results show that achievable maximum group-index change is about 1.4 and a 10-mm-long device can advance/delay a 2-ps pulse by 15.9 ps with pulse broadening factor equaling to 2.