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

[Ashton]

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]

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]

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]

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]

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]

well, yes and no, this one I cant fault them on, because it really IS unusual, however they blew it WAY out of proportion...