Removing Dielectric Coatings?
OK, so maybe this shouldn’t be in the “Optics Cleaning” department, as it means cleaning off the coatings entirely. Exactly the opposite of the usual objectives, above. Here’s the situation. You have some dielectric coated mirrors that have been seriously damaged, perhaps by improper cleaning, and thus useless for their intended purpose – say inside a laser resonator. Is there any way to remove the coating so they could possibly be used, say as a beam sampler or weak lens (if curved)? With old soft-coated optics, this would be no problem as almost any solvent will dissolve the coatings. But with modern hard-coated optics, the coating itself may be harder than the substrate and impervious to almost anything that won’t also damage the substrate. The use of any abrasive would require repolishing of the substrate at the very least. A strong enough acid to dissolve the coating would probably also etch glass. The only way I know of to do this that even comes close to removing the coating wit
