A laser amplifier system includes a gain medium having a longitudinal axis and a plurality of sides substantially parallel to the longitudinal axis. The laser amplifier system also includes a waveguide having a plurality of inner surfaces. Each of the inner surfaces is optically coupled to one of the plurality of sides of the gain medium. The waveguide also includes a plurality of outer surfaces. The laser amplifier system further includes a cladding optically coupled to the outer surfaces of the waveguide.
STATEMENT AS TO RIGHTS TO INVENTIONS MADE UNDER FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
 The United States Government has rights in this invention pursuant to Contract No. DE-AC52-07NA27344 between the U.S. Department of Energy and Lawrence Livermore National Security, LLC, for the operation of Lawrence Livermore National Laboratory.