Hy,
thanks for so much feedback. I got a couple of new ideas!

Steve:
to our quadrant-diode discussion - If you want to fix a beam on your optic table you need two mirrors and two pinholes (or points) through which your beam runs. The setup (beampath) is then as follows mirror M1 then mirror M2 and then pinhole P1 and at last pinhole P2 (position of P1 and P2 define where your beam runs on the optical table).
With M1 you align to P1 when it is in center you align the beam with M2 to P2.
This causes that you have to realigne M1 to P1 as it does not go through P1 anymore when you play with M2. This might now sound totally confusing
but you need 4 piezos 2 for each mirror to tilt in x and y as well as 2 quadrant diodes to replace your pinholes.
The setup I just described is shown at:
http://www.newfocus.com/Online_Ca...pnote4.pdf
in figure11.
If I totally confused you now and you want still go on to discuss it please e-mail me - Optics is fun thats right but I think we are drifting off of the topic of this forum ;-).
Please also note that this is not my problem!

Greetings,

Klaus