Issue with my green..

[Paulingtons]

Hey guys,

I understand there is a sticky on this, but I feel it's fluctuating too fast and too early for it to be a temperature issue, as they say the duty cycle of this laser should me a maximum for 1 minute. Also, this would mean the optimum temperature of the laser is as soon as it's turnt on until 0.4 seconds after, can't be right?

I have a green I bought a fair while ago, here's a picture detailing power etc:

.

I am having the issue that as I turn it on, it's very bright, but then fades instantly into almost the kind of visibility I'd associate with a very low power red.

Video of it in a dark room, no fog:

YouTube - Laser test.

I am unsure what can be causing this issue, if I fire the laser with no lens so unfocused, the shape the diode outputs changes and then stops at a different shape which is much lower power.

Any help appreciated, cheers!

 

[Gryphon]

Low batteries, over driven pump, or poor crystals are things that could be causing this.

Low batts would cause a nice peak and drop off shortly afterward
An over driven pump maybe shifting its wavelength causing a drop in converted light
Poor crystals may not be able to sustain the high input/output and heating up, dropping effiecency with it

Also, some members might nag you on the size of that pic(its a big big even for a HD widescreen)

 

[Paulingtons]

Low batteries, over driven pump, or poor crystals are things that could be causing this.

Batteries are freshly charged 2x2600mAh. Tried 3 different sets of batteries too.

As for the others, I think I may have to take this apart for that!

 

[goninanbl00d]

The crystals themselves are most likely damaged and/or misaligned.

The sudden dip in brightness and the change in beam shape is called mode hopping. It's a common occurance amongst cheap greenies.

Unfortunately, there isn't much you can do to repair the crystals themselves.

Have you tried letting the laser warm up in your hand before using it?

 

[Paulingtons]

Letting it warm up makes no difference at all..

 

[goninanbl00d]

In that case the crystals are probably damaged.

If it really was <200mW, the module was probably being overdriven. That could have led to crystal damage over time.

 

[Paulingtons]

In that case I'll likely keep it for fun.

It's putting out major IR, my camera is sensitive to it and after a few seconds the aperture is pure white, no green at all.

Cheers all!

 

[goninanbl00d]

In some cases (as with my old green module), it ends outputting more IR than green. The IR was visible with safety goggles on.

If that happens it's a clear sign that the crystal is f#cked. Not much you can do, otherwise.

 

[cistercian]

Sadly, I have seen this before.10 years ago when a pen like that was 350 dollars or so.The tolerances are critical in the crystal stack, and depending on how they stack up, you get a low output that increases as it warms up or a high output that fades as soon as the assembly heats up.You have the latter.The mode hopping comes from the crystal set in your pointer being overdriven by the pump given it's tolerances and size/heatsinking.It is incurable.On the upside, you are not out too much money.Buy a couple more and you may hit the lottery with a unit that takes a couple of seconds to come up to inexpensive high power.

Good luck.