Homebrew PCBs

I understand about lost power.   In my example the beam was round to start
with but I had to filter out secondary beams to provide an as clean beam as
possible and I was not looking for max power.

 

My point was exactly that:  The beam expander + big aperture would be
similar to a small aperture and no beam expander: both would lose
significant power.

 

To preserve power as discussed, use either a curved mirror in one dimension
or a cylindrical lens.

Bertho

 

From: Slavko Kocjancic   Sent: Tuesday, November 19, 2013 03:59



On 11/19/2013 09:39 AM, Boman33 wrote:

Note, my example had nothing to do with obtaining a small spot for
developing artwork or PCBs.  It is a common method for obtaining a "clean"
laser beam focused on infinity.  It was used for optical experiments.  A
beam expander will not remove any secondary laser beams, they too will be
expanded.

A beam expander plus an aperture presumably will be the same as just an
aperture of a smaller size directly in the beam.  For example, if the laser
beam is 1 x 3mm, a 1mm aperture would give a 1mm beam.  Would that not be
identical to a 10X beam expander with a 10mm aperture?

Bertho

Doesn't matter. 
If beam is 1x3mm and I need 1x1mm with this method I lost 2/3 of power. It's
only masking unwanted portition. And expanding and companding losse some
power too. I just wonder if I can remove that with lens (colimator) tilted.
Or some additional lens tilted...  ...need to try, but for now I'm focused
ti try the LED aproach