A coated optical component includes an optical component and a conformal coating. The optical component is crystalline calcium fluoride and the conformal coating is an atomic layer deposition (ALD) coating in contact with a surface of the optical component. The ALD coating includes a metal fluoride ALD coating having a metal different from calcium. The ALD coating can include other metal oxide or metalloid oxide ALD coating layers. The method for making the coated optical component includes depositing an atomic layer deposition (ALD) coating on a surface of the optical component, where the ALD coating can be a metalloid oxide, a metal oxide, a metal fluoride having a metal that is different from calcium, or combinations of these. Sulfur hexafluoride is used as a fluorine source in the ALD process.