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

[Bill Marriott <btk@pacbell.net>]

Ric Rokosz wrote:
> 
> On Tue, 19 Sep 2000, Bill Marriott wrote:
> 
> > super polished brewster windows. The criteria we used was:
> >
> > 1) less than 2 angstrom surface roughness
> 
> What type of test did you use to measure the surface ?

Well, we sent samples to Lawrence Livermore Laboratory, who tested them
for us.....I assume they used a micro profilometer

 
> > 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.
 
> Did you use a teflon based polisher to get this super polish Bill?

No. I am aware of teflon based polishing system, and keep talking about
doing some research into it, the original article about such I believe
is in one of the optics journals from the early 70's

The process we used involves a particular cerium product (Hastilite PO),
with citric acid added to keep the PH at 4, as per an article out of
LLNL...

BTW, Hastilite PO, available from Universal, is a wonderful polishing
compound that works great with Pyrex. Mixed fairly thick for stock
removal, and more dilute works great for figuring, and in this reporters
opinion, makes a great replacement for rouge/barnsite type compounds,
paricularily as far as clean up issues

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