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View Full Version : Anamorphic prisms- FA or mode correction?



goninanbl00d
11-05-2010, 21:28
OK, so, really stupid question. O_o

I've done what I can to read up about these things, with not much luck.

I just want to know- are they for mode correction or for FA correction?

Some say they simply fix the highly-divergent fast axis, while others have said they circularize the beam.

So what's the case with these, then? Do you need seperate optics after the prisms to get a round beam profile, or do the prisms also fix up the beam profile as well as correcting the fast axis?

Thanks in advance.

allthatwhichis
11-05-2010, 23:51
I believe it is FA correction and I truly don't feel we are going to get a round beam out of these. Perfectly square is the best we can hope for in my opinion. I think we might want to start looking for ways to expand our greens a bit to match the red and blues a bit more.

goninanbl00d
11-06-2010, 00:23
Mmm, didn't think it'd work miracles with the beam profile. O_o

Anyway, I'd just be happy if the FA and SA have the same divergence. You could probably adjust your green out to match it, and the red too.

badger1666
11-06-2010, 00:52
what reds and blues are you using that are bigger than greens ?
my problem is the other way round i have 640nm @.8mrad ,445 @1mrad, and a fat arsed green @1.5mrad

Doc
11-06-2010, 03:53
A tilted bi convex lens can go some way to circularising a beam.

goninanbl00d
11-06-2010, 21:22
Ahh, so it is for divergence correction.

Thanks for clearing that up.

I wasn't expecting miracles either, but if it's got less than 2mRad divergence, I'm happy.