▎ 摘　　要

NOVELTY - The device has a one-dimensional photonic crystal which is provided with a defect layer (3). Front and back surfaces of the defect layer are orderly arranged with a multi-layer photonic crystal unit. The multi-layer photonic crystal unit is provided with a graphene layer (1) and a silicon layer (2). The central defect layer is made of a phase change material i.e. vanadium dioxide (VO2). USE - Terahertz wave band tunable multifunctional beam control device used in terahertz wave communication and sensing applications. ADVANTAGE - The device can realize band-pass filtering and perfect absorption switching function of two beam modulation in the terahertz band by changing the phase state of vanadium oxide. DETAILED DESCRIPTION - An INDEPENDENT CLAIM is included for a tuning method of a terahertz wave band tunable multifunctional beam control device. DESCRIPTION OF DRAWING(S) - The drawing shows a schematic perspective view of the terahertz band tunable multifunctional beam control device. (Drawing includes non-English language text) Graphene layer (1) Silicon layer (2) Defect layer (3)