▎ 摘　　要

We propose the use of graphene chirped-superstructure bragg gratings for far infrared frequency. Grating structure is created by placing graphene layers between the silicon waveguide. We show that tuning of frequency band is possible by changing the graphene chemical potential, graphene layer's period and gap between them. The reflectance is increased by increasing the graphene chemical potential. The electric field response show that energy is better filtered when number of graphene layers are increased. The proposed tunable chirped-superstructure gratings can be used as reflector, filter in far infrared frequency region.