▎ 摘　　要

NOVELTY - The device has a composite structure which is expressed as: HLGHHGHHGLH, where H is uniform dielectric sheet one with low different and L represents uniform dielectric sheet two respectively refractive index, and G is a graphene single layer. The thickness respectively of the uniform dielectric sheet one and the uniform dielectric sheet two is quarter of each optical wavelength. The composite structure has an optical component. The electric field has a local function. The three graphene single layers are just respectively at the strongest position of the local electric field corresponding to one of the optical sub-shapes. The third-order nonlinear effect of graphene is greatly enhanced, so as to realize low threshold optical bi-stable state, double stable state threshold is low to the level of 100MW/cm2 USE - Optical logic device based on period-doubling (PD) photonic crystal and graphene composite structure for use in full optical communication. Uses include but are not limited to optical domain, transmission, relay, decision, timing, amplifying and shaping. ADVANTAGE - The third-order nonlinear effect of the graphene is greatly enhanced, so as to realize low threshold optical bi-stable state. The threshold of the optical bistable state in the structure can be low, 100MW/cm 2 is 3 orders of magnitude lower than the threshold value of the light-emitting diode (LED) photonic crystal and the graphene composite structure. The interval between the upper and lower threshold values can be flexibly adjusted by the increase of the chemical potential and incident wavelength of graphene. The optical logic device has high optical splitting shape, the electric field has local effect, three graphene single layer is just respectively in one of the most strong position of the local electric field corresponding to one optical sub-form. DESCRIPTION OF DRAWING(S) - The drawing shows a schematic view of the centrosymmetric PD photonic crystal and graphene composite structure schematic diagram of sequence number N= 2. Graphene single layer (G) Uniform dielectric sheet one (H) Uniform dielectric sheet two (L)