Problematic beam spot...

[MechEng3]

This is Drlava's lens setup with the G-2 lens. I have redone the whole setup twice and to no avail get the "dual diode cross" in the spot in nearfield removed. Is this normal for this optic setup? Yes they are clean, the lenses, and are still clean. Just wanted to see other results before I pinhole it to get it clean up a bit. Maybe I need to try another diode as the culprit may lie at that level....just want to see what others have found. First pic is at near 20mw and second is on black foam at 400mw. Produces a very tight beam....it's just those "spot wings" I can't take....even though they won't be seen scanning.

[andy_con]

arent the "wings" cause the actual lens from memory same as red diodes. there is a post on here about it somewhere

[MechEng3]

I am looking...if it is normal than my mental stability has not faultered too far with this. Just wanted to see what others have as a spot.....before I yank the diode and start over again.

Found it....sorry for the double postage....http://www.photonlexicon.com/forums/...ght=spot+wings

Guess it will be a pinhole filter device coming up.....

[Solarfire]

I'm currently testing setups with different collimators, prisms and cylinders and this effect seems to be more or less typical with cylinders since I have only observed this with the cylinders and not with prisms. This appears to be a result of minimal lens internal reflections ocuring due to the fact that the AR coatings are never 100% this will result in a slight line generating effect which is typical of a Cylinder lens.

Frank