Bend property of few-mode ring-core fiber supporting seven spatial modes for mode-division multiplexed applications

Few-mode ring-core fibers (FM-RCFs) have been widely consider as promising optical fibers in the mode-division multiplexing transmission system, for reducing inter-modal crosstalk. In this paper, we present a numerical analysis on the bend property of a few-mode ring-core fiber supporting seven spatial modes for practical necessity. The factors for simulation contain the bend loss, modal effective area, spatial density, effective refractive index, propagation constant and effective index difference. The results indicate that the FM-RCF also can keep good properties under bending conditions. In order to further explore the bend property of the FM-RCF, the effect of the refractive index difference between inner core and outer core on the bend property of the FM-RCF, is also investigated. The results show that the refractive index difference also plays a significant role in mitigating the intramodal nonlinearity and benefiting the bending insensitivity.