Spiral structure type long-period fiber grating interferometer and manufacturing method thereof

The invention discloses a long-period fiber grating interferometer based on a structural micro-nanofiber and a preparation method of the long-period fiber grating interferometer. The long-period fiber grating interferometer comprises a micro-nanofiber II, wherein a middle part of the micro-nanofiber II is wound on a conical region of a micro-nanofiber I; the periodic spiral winding part in the middle of the micro-nano optical fiber II and the conical region of the micro-nano optical fiber I meet the phase matching condition of the long-period grating so that the structural micro-nano optical fiber long-period grating is formed; two ends of the micro-nano optical fiber II are butted and coupled; when resonant coupling of an optical signal in a grating area meets a long-period grating phase matching condition, part of light energy of a corresponding wavelength is coupled to a spiral winding part of the micro-nano optical fiber II, then is inputted to the grating again through a coupling loop, and is further cou