Re: ATM What does a "super polished" surface look like?

[Bill Marriott <btk@pacbell.net>]

Since I'm stepping in here mid topic, I'm not sure of the original post,
but in regards to the topic, what does a super polished surface look
like, I can make the following comments.

In the past, we have had to make in our shop, for the laser industry,
super polished brewster windows. The criteria we used was:

1) less than 2 angstrom surface roughness

2) The defect free surface (or at least 10-5) must remain so after
etching in a dilute Hydrofluoric (HF) solution, which reveals defects
filled in by the flowing of glass during the polishing process.

Food for thought

Bill Marriott
http://www.starlightoptical.com
telescope/optical stuff