Photonic crystal fiber

The invention discloses a photonic crystal fiber. The photonic crystal fiber is characterized by comprising a core layer, a cladding layer and a coating layer from inside to outside, wherein the crosssection of the fiber is circular, the core layer, the cladding layer and the coating layer are concentric, the core layer is the inner-most layer of the fiber, the center of the cross section of thecore layer is a circular hole, the cladding layer is internally uniformly provided with multiple semi-circular air holes, the cladding layer comprises five clamping layer rings, each cladding layer ring is formed by same-size semi-circular air holes connected in sequence, sizes of the semi-circular air holes in the cladding layer rings increase in sequence from inside to outside, the coating layeris the outer-most layer, the cladding layer is prepared by a silica crystal material, and the core layer is prepared by the silica crystal material or a Schott glass (schott SF57) material. The photonic crystal fiber is advant