20mW green laser out of focus

[lysozymes]

Hi guys,

I got a 20mW green laser from ThinkGeek several years ago.

The laser worked great, with several km range. Great for showing constellations to my nephews.

The green laser has suddenly become a a big smear across the wall instead of the green dot. Is the diod displaced?

Any tips on how to realign the diode? I recently moved to Singapore from Sweden, so the laser could have gotten a bumpy ride in my luggage.

Thanks!

 

[rocket689]

First thing I would try is be focusing the lens. Most 532nm lasers have the lens threaded. Sometimes this gets turned and makes a big dot instead of a small one.

If the IR pump diode was mis-aligned, it would most likely not emit any green at all. :beer:

Edit: Another thought is to check if there are any smudges on the lens...

 

[Flaminpyro]

This dose sound like a focus problem but if it is not then it could be the Xtals got miss aligned in the move.

There are little xtals inside that the beam must go through and it possible they have become miss aligned.

Good luck...

 

[BShanahan14rulz]

+1 on cleaning the lens. When you say smudge, is it a circular smudge? That would indicate a focus problem because the dot is a circle and when defocused, stays a nice, round circle. If it is more of a big blur with no defined edges, it probably has some gunk on the lens

 

[lysozymes]

thanks guys for the amazingly quick response!

ok, will start cleaning the lens first. if that doesn't do it, I'll open it up and check the xtal alignment.

thanks rocket689 for suggesting the threaded lens. I checked, the whole thing is screwed on pretty tight with the laser warning sign still on top of the thread.

wish me luck guys!

 

[jimdt7]

Good luck ! And remember never look at the diode while it is on !

Jim