摘要 |
In a fiber bundle (100) in which one ends of a plurality of optical fibers including cores (111a-111p), respectively, are bundled as a bundled portion, the fiber bundle includes in the bundled portion a clad (112a-112p) having a refractive index less than that of each of the cores and surrounding the cores so that the cores are positioned near to each other with a minimum distance left between two adjacent ones of the cores. The minimum distance is decided so that transverse modes of laser beams propagated through the above-mentioned two adjacent ones of the cores do not affect each other. Typically, in the fiber bundle, different ends of the optical fibers are kept separated as a separated portion without being bundled. In this case, each of the cores may include a laser active material which produces, when excited by an excitation beam incident to the different end of each of the optical fibers, the laser beam propagated through each of the cores from the different end of each of the optical fibers to the one end of each of the optical fibers. <IMAGE>
|