Abstract: Methods and apparatus are provided for igniting, modulating, and sustaining a plasma for various coating processes. In one embodiment, the surface of an object can be coated by forming a plasma in a cavity by subjecting a gas to an amount of electromagnetic radiation power in the presence of a plasma catalyst and adding at least one coating material to the plasma. The material is allowed to deposit on the surface of the object to form a coating. Various plasma catalysts are also provided. Coatings can include any material, for example, carbon nanotubes, BaTiO3, Cr2O3, hafnium oxide, 3Al2O3.2SiO2, Al2O3, SiAlON, MgAl2O4, TiN, and TiO2.