What's wrong with this laser?

[Mac82]

I got this (chinese) Small Sun ZY-850 green laser. It was said to be a 100 mw laser but after some google-research it tuned out to be only a 30 mw. O well, I thought, that's not bad either cause max 5 mw is allowed in Holland.
I'm pretty happy with it and at night the beam is clearly visible for aprox. 300 meters.

But I noticed that when you shine at a smooth surface you see a dot and something that apearse to be some sort of grid. Is that poor quality optics/lense or IR filter? I attached some pictures. :undecided: I shot one pic of the surface and two directly into the diode/beam with a very fast shutter time.


By the way, by using a screwdriver on that screwy-thing (pot?) you can make it brighter (and shorten your battery life!)?

Hope somebody knows....

 

[Gryphon]

The diffused light around the dot is scatter. Its mainly caused by dirty optics. Try cleaning the aperture lens with a proper cloth or even a q-tip with a small amout of rubbing alcohol. If the scatter remains from dirty optics inside the module, don't sweat it, nothings perfect and should not detract from the lasers overall power.

The screwy-thing is a potentiometer, or adjustable resistor. Turning it and lowering your resistance will increase current to your diode and produce a brighter beam at the expense of shortened diode and battery life. Best not to mess with it too much

 

[Emc2]

That is a dirty or scratched lens. You have to clen it with a Q-Tip and get all of the oil off of your fingers before doing so.