Date: Thu Oct 16 16:58:08 2008

Author: --- cbettis

Subject: Re: DCS # for Lloyd's Mirror


Sure Gary,

I used a spatial filter on a laser to expand the beam and give me a
nice clean diverging beam. Then I raised a large 25 cm x 25 cm piece
of plate glass up into the beam so that it just grazed the sueface. As
the reflected spot on the wall a few meters lowered into the direct
spot, beautiful fringes appeared. I had shimmed the plate glass to get
it at the right angle. I tried an optical flat earlier but didn't get
enough of a effective aperture taht way. It was not necessary to have
the glass silvered because of the grazing angle.


Quoting Gary Karshner :

> Cliff,
> Can you enlighten us as to what worked well.
> Gary Karshner
> At 02:12 PM 10/16/2008 -0500, you wrote:
>> Do we have a DCS number for this? I was asked for it today and came up
>> with something that worked well; I would like to catalog it. It is
>> mentioned in several of our references (e.g. DR O-410). I could be
>> just overlooking it after tiring myself looking at fringes.
>> Cliff