IMPROVED REFLECTION/ABSORPTION COATING FOR LASER SLABS

An optical waveguide for guiding electromagnetic waves. One example of an optical waveguide includes a waveguide substrate, at least one layer of low index optical coating formed on a surface of the waveguide substrate, and a thin layer of metal formed on a surface of the at least one layer of the low index optical coating, where the at least one layer of low index optical coating is disposed between the waveguide substrate and the thin layer of metal. The thin layer of metal can have a thickness in a range of about 5 nm to about 20 nm. In one example, the thin layer of metal is chromium.