A 1-J laser was designed to launch light down 16, multi-mode fibers (400-μm-core dia.). A diffractive-optic splitter was designed in collaboration with Digital Optics Corporation1 (DOC), and was delivered by DOC. Using this splitter, the energy injected into each fiber varied <1%. The spatial profile out of each fiber was such that there were no "hot spots," a flyer could successfully be launched and a PETN pellet could be initiated. Preliminary designs of the system were driven by system efficiency where a pristine TEM00 laser beam would be required. The laser is a master oscillator, power amplifier (MOPA) consisting of a 4-mm-dia. Nd:YLF rod in the stable, q-switched oscillator and a 9.5-mm-dia. Nd:YLF rod in the double-passed amplifier. Using a TEM00 oscillator beam resulted in excellent transmission efficiencies through the fibers at lower energies but proved to be quite unreliable at higher energies, causing premature fiber damage, flyer plate rupture, stimulated Raman scattering (SRS), and stimulated Brillouin scattering (SBS). Upon further investigation, it was found that both temporal and spatial beam formatting of the laser were required to successfully initiate the PETN. Results from the single-mode experiments, including fiber damage, SRS and SBS losses, will be presented. In addition, results showing the improvement that can be obtained by proper laser beam formatting will also be presented.