Green 532 not focussed ?

[hobbybob]

Hello there,

I am relatively new here, have been lurking around for a week.
Have ordered some stuff here and after some email exchange with Rob from LaserWave UK, i have decided to ask some questions here, and show my hobby builds in another topic.

First i have a question about my green 532 1000mW laser.
It doesn't seem that focussed (or is it collimated ?) as my blue 75mW for instance. Have some pictures to illustrate.

Up close the dot appears bright and as a single dot:


Then when i look at the beam at a distance of 5 metres it's like 2cm wide !
Check it out:



It looks like a nice round dot in the top left and a garbled dot below it down to the right lowerhand corner. Especially when compared to my blue 75mW laser, which has a nice round dot at the 5 meter distance:



Ehm... it's about the comparison of the lasers, not how many spiderwebs i got ok ? I will let my cleaning lady know how bad i look at the internet now

What could cause this ? it's very wide, i like it to be a nice round dot.
Is this a failure of the optics ? The laser module is a Shanghai Optics & Laser Century co GL532H-1000, made in Dec 2007.
When i bought it a few weeks ago, it measured 988mW on a coherent meter. But i can't remember having seen the dot so large.
Well, it might have been, but i might have been to excited being almost the owner of 1W of Green that it might have troubled my judgement....
Hope this can be fixed (could some lenses fix this ?) or someone has a similar experience and solution ?

Thanks in advance.

Kind regards from the Netherlands,
Dimitri

[ledfreak3d]

Hi Dimitri

could be a number of causes
pump beam is not focused correctly.
may be missing its target slightly.
bad crystals
may also be a alligment issue.
or could even be the diode
but since the output power is stil ok its probably the optics aligment

ive also seen several cni style heads and cni rebranded laser modules with slightly loose pump beam optimiser lenses in them.

since your in the netherlands.
i should be able to realligne the optics path for u and do some temperature tuning to optimize the power output

[hobbybob]

Wow that's a quick reply, with lots of terms i can follow to some extent and think are mighty interesting. Would it be ok to watch with you as you go along, since i think it's very interesting for me to learn about. I am based smackdead in the center of the Netherlands, would love to make an appointment for this. Will sent you PM.

[Doc]

My 1Watt CNI was similar, though not quite as bad. I managed to shrink it by adjusting the focus ring.

[hobbybob]

Yeah but the ring in the front i can turn off completely with nothing happening, this is just a ring with a hole in it. The Lasever had really a turnable lens. This lens looked "Glued" on under the unscrewable cap. Will make some pictures of it. one sec.

[hobbybob]

Pictures made. Cap unscrewed:


And a close up of the head without cap:


I can see two small holes which can be used to "turn" the lens, although it's all kitted.
But i will wait for Ledfreak3d's reaction, i sent him a PM on his offer to help me (before i break another laser....)

[Doc]

From what I can see (posting from my phone) the focus ring is the part surrounded with glue (what Rob described as "chinese atomic superglue"
I would only try adjusting it if the problem is severe, you don't want to break your laser.

I've recently divereged my green again to be a better match for my 650 red.

Fat beams are a non issue for beamshows

[ledfreak3d]

yea that ring wil only adjust the focus.
but wil not remove any artifacts or beam quality issues