A method of cleaning a diffraction grating preferably includes exposing the grating surface to an aqueous base to remove an organic photoresist mask thereon; rinsing the grating surface with de-ionized water; oxidizing acid solution (such as Nanostrip.TM. or Nanostrip.TM. 2X) to remove metallic contaminants and residue organic compounds; rinsing the grating surface with de-ionized water; exposing the grating surface to an oxygen plasma ashing process using reactive oxygen species to oxidize and remove fluorinated hydrocarbon residue; exposing the grating surface again to an oxidizing acid solution to remove metallic contaminants and residue organic compounds; and rinsing the grating surface with de-ionized water.
FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
 The United States Government has rights in this invention pursuant to Contract No. W-7405-ENG-48 between the United States Department of Energy and the University of California for the operation of Lawrence Livermore National Laboratory.