Study On Single-mode Fiber With Large Mode Area And Low Bending Loss

In order to meet the demand for high density wiring network, the topic that how to guarantee the bending sensitivity of fiber in the limited space has become a hot topic in the world. Although small mode field diameter of the fiber can achieve low bending loss, there are serious non-linear effects at high power. For large mode field diameter fiber, the nonlinear effects can be resolved, but it will bring increased bending loss. Based on a trench-assisted bend-insensitive optical fiber, we propose a novel optical fiber with core refractive index of parabolic profile in this paper. In this configuration of optical fiber, refractive index difference of core-cladding, core radius, the distance from core to trenched layer are three important parameters affecting cutoff wavelength, mode field diameter and the bending loss. This study discussed the influences of parameters of the novel fiber on mode field diameter and bending loss under single-mode operation conditions. Study results have shown that: At1550nm wavelength, the maximum mode field diameter of our single-mode fiber is16.8μm and the effective area is221μm which is about3times that of standard single mode fiber. And the optical fiber bending loss can be very well controlled. The conclusions have an important guiding significance of bend-insensitive fiber design and development of high-power lasers.