Wideband slow-light propagation with no distortion in a nanofiber-plane-grating composite waveguide

Abstract

A nanofiber-plane-grating composite slow-light waveguide to achieve wideband slowlight propagation with no distortion is proposed. The waveguide is formed by embedding a tapered nanofiber into a V-groove on a plane-grating surface. By optimizing the waveguide structural parameters, a slow-light effect with bandwidth of about 1453 GHz is obtained. Based on finite-difference time-domain (FDTD) method, we analyze the waveguide’s optical properties and slow-light characteristics. Simulation results show that a picosecond optical pulse propagating in the slow-light waveguide can be delayed for about 980 fs and without distortion. The group velocity of the optical pulse can be reduced to about 0.3c (c is the speed of light in vacuum). This study will provide important theoretical basis and innovative ideas for the development of new-type slow-light elements.