How do you clean VPHGs?

VPHGs, whether they are AR coated or not, can be easily be cleaned just as you would any other glass optic to remove fingerprints, dust, and contaminants. Use the standard optics cleaning method of “drop and drag”. Gently wipe the grating with a clean, lint-free cloth/wipe using acetone or alcohol without much pressure; reagent-grade methanol or Windex may also be used. Do not use MEK, polishing compounds, etc. Hard rubbing with such chemical or polishing compounds may damage the AR coating. AR coated surfaces will pass the “Scotch Tape” test.