Structure design method for graded-index optical fiber

The invention discloses a structure design method for a graded-index optical fiber, and the method comprises the steps: 1) inputting optical fiber initial structure calculation parameters, including a function of a refractive index profile, a working wavelength lambda, a refractive index of a fiber core, a refractive index of an outer cladding, a radius of the fiber core, and a radius of the outer cladding; the area where the fiber core and the cladding are located is divided into N refractive index layers according to the refractive index; 2) determining the value range of the effective refractive index neff of the optical fiber mode according to the refractive index of the fiber core and the refractive index of the cladding; performing linear discrete value taking on the neff; 3) for each LP mode order m, according to the characteristic matrix corresponding to each effective refractive index sampling value, solving the numerical solution of the effective mode refractive index neff and the number of the effe