Fig. 1. Structure of the fiber. (a) Structure of the elliptical core graded-index fiber; (b) refractive index distribution on the ellipse

Fig. 2. Group velocity dispersion and relative group delay for different transmission modes. (a) Group velocity dispersion; (b) relative group delay

Fig. 3. Variation curve of phase mismatch with wavelength during MI and PC process

Fig. 4. Gain distribution for different modes. (a) Results obtained from the numerical solution; (b) result obtained from the analytical solution

Fig. 5. Crosstalk curves obtained from the numerical solution and semi-analytical solution. (a) Effect of LP₀₁ mode on other modes; (b) effect of LP₀₂ mode on other modes; (c) effect of LP_11b mode on other modes; (d) effect of LP_11a mode on other modes; (e) effect of LP₂₁ mode on other modes