Originally Posted by
smartcut
Many thanks for the informations.
I already tried a very simple system that (roughly) works, before to purchase any optical (and expensive !) device.
I used a copper tube that acts as a wave guide and a mode mixer. The beam is quite cylindric at the output. And it insures that the beam will not burn the rubber seal of the lens : the tube limits the beam expension just before the lens.
Of course, this is just something to wait until a better and more serious system ! (to get a true TEM00 beam).
But in fact, my experiments deal with ceramic processing trials, so a high quality beam is not required. My most important problem was a good drive of the beam through the lens without any damage to the lens holder.
Nevertheless, I will get some informations about the optical systems described.
Thanks again !