Groove-assisted random coupling multi-core optical fiber

The invention discloses a groove auxiliary type random coupling multi-core optical fiber. The random coupling multi-core optical fiber comprises an outer cladding layer and n identical groove-assisted fiber cores arranged in the outer cladding layer, wherein n is greater than or equal to 2 and less than or equal to 12; each groove-assisted fiber core sequentially comprises a low-doped fiber core, a high-doped fiber core, an inner cladding and a low-refractive-index groove-assisted layer from inside to outside; each groove-assisted fiber core only supports a single mode, namely HE11, and if the polarization state is considered, the HE11 is divided into x polarization HE11 and y polarization HE11; therefore, the number of excited super-mode orders is the same as that of the groove-assisted fiber cores, and the modes with larger other orders are cut off. The inner cladding and the trench auxiliary layer with the low refractive index are combined by different values, so that electromagnetic field overlapping can