Modal characteristics of a novel multicore optical fiber

In order to achieve high-power and high-brightness fiber laser beams,based on the strong coupling mechanism of evanescent field,the modal field characteristics of multicore fibers,including a bundle of multiple micro/nano fibers or a bundle of multiple micro/nano fibers and large core fibers,were numerically simulated and theoretically analyzed with finite difference time domain(FDTD)method.The result shows that good coupling among the fibers can be obtained in a micro/nano fiber array and that the modal field is flattened by the micro/nano fibers in the bundle of multiple micro/nano fibers and large core fibers.The result is useful to further development of high-power lasers and amplifiers.