"negative" divergence - good idea in general?

[ixfd64]

Wicked Lasers' "Pulsar" lasers are among the few lasers that have a "negative" divergence - in other words, the beam converges to a point and then diverges again. This would obviously increase the burning distance. However, very few laser models have this feature. Is it generally a bad idea to use a "negative" divergence?

 

[darklandz]

i mainly use my lasers outside for long distance pointing. i noticed with the pulsar that the divergence was pretty good, u could see the dot at night well over a KM away.
for me a less diverging beam would be a better choice.

 

[Helioplasma]

Mine has a positive divergence of 0.93mRad and a horrible beam diameter @ aperture as usual. before the RMA I had one with 0.08mRad (very noce beam). I don't know why every WLs I had were diverging.

 

[pseudonomen137]

Sorry, but I disagree with you ixdf64. Any laser that is well collimated will converge first. The pulsar has a large initial diameter and its easier to see this with despite the fact that the laser never actually converges to a tight focus (its focus still has a relatively large diameter). Greenies are the same but it may be harder to see the smaller change in diameter from the aperture to the focus

 

[cyclonite]

Yeah my laser starts off with a 'big dot' in front of the focal point and at some point the focal point is obvious and as you move away the dot becomes big again. Unless of course I focus it to 'infinity'

The Pulsar lasers probably have a further focal distance on its lense.

My laser can shine miles away and still be visible as well. I'm only using a Sony 16x diode with 240mA in an AixiZ housing.