High numerical aperture multicomponent glass fiber

High-numerical-aperture (N.A. 0.53) multicomponent glass fibers with 20 dB/km optical loss have been obtained. Glass containing BaO is most promising for fabrication of high-N.A. low-loss optical fibers over a wide wavelength region. The BaO-core glass/multicomponent-clad glass fibers show the following notable characteristics: relatively low optical loss in the 0.6–1.3-μm region, small N.A. wavelength dependence, high effective N.A., large bandwidth due to mode coupling, and high coupling efficiency to LED.