Compact Single-Mode Nd-Doped Silicate Glass Multitrench Fiber With 40 μm Core Diameter

We report a 40 μm core-diameter single-mode multitrench fiber (MTF) based on Nd-doped silicate glass. Both the delocalization effect and leaky nature were considered in the design of the MTF. The silicate MTF was designed and fabricated using the rod-in-tube method. A maximum laser output power of ~8.4 W with a slope efficiency of 54% was obtained from a 10-cm-long single-mode MTF.