The present invention relates to fiber bundles and methods for making fiber bundles. According to one embodiment of the invention, at the endface of the fused fiber bundle, the ratio of the cross-sectional area of the endface to the cross sectional area of the plurality of optical fibers is at least about 2.5. According to another embodiment of the invention, a fused fiber bundle includes a plurality of optical fibers, and a glass tube surrounding the terminal segments of the optical fibers, wherein the refractive index of the glass tube is less than the refractive index of the claddings of the optical fibers. Other embodiments of the present invention provide methods for making fused bundles.