Details
Usually these coatings are used in multi-frequency laser output systems (e.g. frequency doubling).
This coating provides very high transmission at two different wavelength. Typical wavelengths and reflection curves of an AR coating suitable for the prevalent laser system output at 1064nm and 532nm are shown below.
Coatings are provided by Ion Beam Sputtering (IBS) or Electron beam evaporation with/without Ion assistance coating techniques.