CPC Subgroup
G02B 1/18 Coatings for keeping optical surfaces clean, e.g. hydrophobic or photo-catalytic films (G02B1/16 takes precedence)
Full Title
Optical elements characterised by the material of which they are made; Optical coatings for optical elements > Optical coatings produced by application to, or surface treatment of, optical elements (G02B1/08 takes precedence) > Coatings for keeping optical surfaces clean, e.g. hydrophobic or photo-catalytic films (G02B1/16 takes precedence)