Abstract:
We propose a weakly coupled polarization-maintaining few-mode fiber (PM-FMF) design with elliptical-core and bow-tie stress-applying areas. Using a high refractive index core, the proposed fiber can support 32 independent eigenmodes in the 1505−1585 nm band. The combination of the elliptical-core and bow-tie stress-applying area effectively separates the adjacent eigenmodes. The structural parameters of the elliptical-core and the bow-tie stress-applying area of the PM-FMF are optimized using the finite element method. The effects of fiber parameters on the number of modes, the minimum effective refractive index difference (Δ
neff, mim) between modes, the mode birefringence
Bm, the stress birefringence
Bs, and the bending loss are evaluated. The bandwidth performance of the fiber is also analyzed, including the effective refractive index
neff, Δ
neff and differential mode delay (DMD) between adjacent modes. The results indicate that 32 eigenmodes supported by the fiber are completely separated with Δ
neff, min between adjacent modes larger than 1.295×10
−4 in the 1505−1585 nm band. The fiber proposed can improve the transmission capacity and has potential applications in eigenmode multiplexing transmission.