Welcome to Laser Pointer Forums - discuss green laser pointers, blue laser pointers, and all types of lasers



Negative divergence... cant be this simple...

Ashton

New member
Joined
May 25, 2007
Messages
340
Points
0
How does one go about setting up a lens for negative divergence? The reasoning in my head says you just need a convex lens mounted at the right distance from the LD... I know it cant possibly be this simple though...
 



laserrod

New member
Joined
Aug 3, 2007
Messages
342
Points
0
Just put your collimater lens closer to LD than the lens Focal point.
That makes beam waist converge to a point.

If you can find a longer focal lenth Collimater lens the beam waist will be bigger but spead less over distance. KEYWORD: miliradians.

If your laser is spec. .8 milliradians beam spot at 1000 meters is .8 meter diameter. (.0008 X 1000 = )

Hope I didn't write that backwards. ;D ;D


Cheers [smiley=beer.gif]
 

pseudonomen137

New member
Joined
Oct 24, 2006
Messages
2,032
Points
0
Negative divergence? What do you mean by that one? You mean getting the beam to converge to a focus? If you have a collimated beam, you just move the lens a little further from the source, and it will bring it to a focus.
 

Ashton

New member
Joined
May 25, 2007
Messages
340
Points
0
wow it really is as simple as I thought...... so what was so special about WL's pulsar having a negative divergence then? I thought it must have took osme huge engineering marvel to create it or soemthing... what's the big deal?
 

steve001

Well-known member
Joined
Jun 3, 2007
Messages
2,342
Points
83
Ashton said:
wow it really is as simple as I thought...... so what was so special about WL's pulsar having a negative divergence then? I thought it must have took osme huge engineering marvel to create it or soemthing... what's the big deal?
Sounds like another WL ploy on the unsuspecting buying public
 

Ashton

New member
Joined
May 25, 2007
Messages
340
Points
0
well, yes and no, this one I cant fault them on, because it really IS unusual, however they blew it WAY out of proportion...
 




Top