Increase in beam artifacts

[Beren]

Okay, so I own a 200mw focusable from the ever-questionable Kaidomain. I don't have a power meter of any kind, but it's pretty powerful for being less than $200. It does, however, like to go into multimode after extended use with a heavy duty cycle. Therefore, I decided to do some testing today. I left the laser alone for a couple of hours to ensure that there was no smidgen of extra heat left over from its last use. Then I set it up to do an endurance burn that would not require the use of my hands, which normally add a little heat to the laser. The beam was set as wide as possible to make mode switches easy to spot. Anyway, I quit the test after about four minutes since it wasn't hopping yet, and I thought that was good enough. However, it seems that following the test, the amount of uncollimated/scattered green light has increased significantly. It's not terrible, just worse than before (at least I think it is).

Does anyone know what the reason could be for this? Maybe the glue holding the Nd:YVO4/KTP together is deteriorating? Maybe the lenses could be taking damage (assuming they are some kind of poor quality plastic ones)? Diode problems? As long as it's not destroying the laser, it's okay, but any help from someone who is experienced with dpss greens would be greatly appreciated.

Oh, and also, would anyone know where I could find someone with a laser power meter in say, Nebraska, or so?

Thanks

 

[diachi]

It might just be dust on the lens, try cleaning the lens with a q-tip, and if that doesn't help take the focusing cap off and try cleaning inside it a little.

Diachi

 

[Beren]

Hmm... I don't think it's dust, mostly because the line-like artifact (one of those kind that bisects the beam) has gotten brighter and longer. Before, it wasn't visible when you were just looking at the dot, but now it is a little bit visible. I'm not sure, but I don't think that it's the result of dust. I wish I could take your advice and open the thing up, but it won't budge, even with those rubber gripper thingies. Maybe I'm trying to unscrew the wrong part?

I would also really like to find someone with a power meter close enough to me so that I wouldn't have to mail the laser. Does anybody know if a community college would be likely to have such a measuring device and if they would allow me to use it?

 

[diachi]

A local university might have an LPM. That line could be a scratch in the lens, or even a tiny bit of hair or something similar .