Optical Fiber for High-Power Optical Communication

Abstract

Abstract:We examined optical fibers suitable for avoiding such problems as the fiber fuse phenomenon and failures at bends with a high power input. We found that the threshold power for fiber fuse propagation in photonic crystal fiber (PCF) and hole-assisted fiber (HAF) can exceed 18 W, which is more than 10 times that in conventional single-mode fiber (SMF). We considered this high threshold power in PCF and HAF to be caused by a jet of high temperature fluid penetrating the air holes. We showed examples of two kinds of failures at bends in conventional SMF when the input power was 9 W. We also observed the generation of a fiber fuse under a condition that caused a bend-loss induced failure. We showed that one solution for the failures at bends is to use optical fibers with a low bending loss such as PCF and HAF. Therefore, we consider PCF and HAF to be attractive solutions to the problems of the fiber fuse phenomenon and failures at bends with a high power input.

Holey fibers for low bend loss

“…When 2R In is much larger than D melted , the fiber fuse propagates in the same way as in SMF. However, no fiber fuse propagates even at an input power of 18.0 W, when 2R In is much smaller than D melted [51,56]. Figure 19A shows a side view of a splice point between an SMF and HAF-A before and after fiber fuse propagation at a wavelength of 1480 nm.…”

“…Furthermore, HAF has a great advantage with a view to avoiding failures at bends under high power [35], because HAF is a low-bending-loss optical fiber [19]. Therefore, we consider HAF to be an attractive optical fiber as a solution for the problems posed by the fiber fuse phenomenon and failures at bends with a high power input [56].…”

Simulation of Fiber Fuse Phenomenon in Single-Mode Optical Fibers

“…They considered that the plasma density of the core decreased in connection with the disappearance of the hole part and that the propagation of a fiber fuse can be controlled even if a high power of 10 W order is input into an HAF. In practice, they observed the dynamics of fiber fuse termination near the splice point between HAF2 and the SMF and found that the termination was accompanied by the evolution of a gas jet in the case of P 0 = 12 W [48] and 18.1 W (6.6 W at 1.48 µm and 11.5 W at 1.55 µm) [51].…”

“…Several researchers observed the dynamics of fiber fuse termination near a splice point between a HAF and an SMF by using a high-speed camera [42], [46], [48], [51].…”

“…It has recently been reported that a hole-assisted fiber (HAF) [41], in which several air holes are arranged near the core of the optical fiber, exhibits high tolerance to fiber fuses [42]- [51]. The fiber fuse propagation in a HAF is affected by both the diameter of an inscribed circle linking the air holes (D hole ) and the diameter of the air hole (d h ) (see Figure 2).…”