LAUSR

Abstract. Rapidly space-division multiplexing (SDM) techniques have drawn attention because the traditional available physical dimensions to orthogonally multiplex data have been almost exhausted. Few-mode fiber becomes a viable option to realize a high-density SDM system. Thus, we propose an air-hole assisted elliptical ring fiber. Four air-holes are introduced surrounding the elliptical ring fiber, and one air-hole is in the core, which can prevent higher-order modes to be cutoff and improve the degeneracy between modes to achieve multiple-input multiple-output-free data transmission. This fiber can support 14 modes in a wide wavelength range from 1.52 to 1.58  μm (h  =  5.0  μm, dx  =  0.3  μm, and dy  =  1.1  μm), and the effective index difference of its adjacent modes is larger than 1.25  ×  10  −  4. The fiber we designed would be a strong candidate for SDM to improve optical transmission capacity.