The present disclosure provides a method for producing a coating. The method may include providing a substrate material and initiating a coating-deposition process to apply a coating material to the substrate material to produce a coating on the substrate material, wherein the coating includes a diamond-like carbon coating. The method may further include monitoring an intensity of hydrogen-alpha emission of a plasma produced during the coating-deposition process and adjusting at least one process variable of the coating-deposition process to facilitate production of the diamond-like carbon coating.