What did I do to my lens

[Kevin Berkshire]

Did you try LaserBits for a new lens?
Kevin

[Richard Rumancik]

. . .Do you agree that the laser is passing through the center of the discoloration on the original picture posted? It looks like residue collected on the lens but not where the beam passed through. It looks like the beam is quite a bit off center on the lens.

I can't speak for Kay but what I was trying to say is no, not necessarily. What I meant by the picture I supplied is that the laser "beam" is comprised of millions of light rays distributed over the face of the lens. The exact diameter enclosing the bundle of coherent rays is hard to say - could be 4mm or 6mm or 8mm. (Kay was thinking on the smaller side like 3mm.) The lens will bend the rays and they will shoot out the flat side of the lens, but they will still be distributed all over the active lens surface. Any contamination on either side of the lens will cause a hot spot and the ZnSe coating will disintegrate. It doesn't matter where on the lens the contamination lands within the beam diamter; it will create a local hot spot as it heats up instead of passing the light rays.

They often put the anti-reflective coating on both sides although I don't know offhand why it is needed on the "exit" side.