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Green diode

pseudonomen137

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how did this guy do this though, and it's a DX laser like mine except it is a 50mw.
http://youtube.com/watch?v=RzCAEi_DzOA&mode=related&search=
Considering he's claiming its a 1000mW laser, I'm not sure I'd listen to anything he says. You can get a roughly collimated beam though by just sticking a strong lens at the right position in front of the diode. Also, The shape in the movie may just appear that way because the camera's sensor is "oversatured" due to oversensitivity to IR and the concentrated amounts of power.

What are you trying to do with the diode though? If you're having problems focusing it, you may either need to move the lens further away, or use a stronger lens. Divergence out of the diode chip can exceed 40 degrees :)o) in the fast axis so it takes a good bit of curvature to force it to a focus.
 



Things

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i don't want to colluminate it so it can go huge distances, but just so i don't have to put the thing i want to burn right in front of the laser and risk damaging the internal lens.
 

pseudonomen137

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i don't want to colluminate it so it can go huge distances, but just so i don't have to put the thing i want to burn right in front of the laser and risk damaging the internal lens.
Well, you need a converging lens to do either of the two. Stick a lens in front of the diode and the further you move it away from the diode, the close it should bring the focus. For your task you want the focus to be a positive distance (instead of a negative focus / diverging beam), so you may need a strong converging lens. Otherwise the distance between the lens and diode may get pretty insane.
 

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here is a movie i made of it burning a piece of black plastic. see how close i have to get the diode till it starts to focus. i don't think you can much smoke in the vid. when i try to focus it, lots of the laser light is not hitting the lens. the camera is ir filtered so it is very powerfull. ha, i just noticed all the burn marks in the plastic ;D ;D
 

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my laser isn't focusing properly, and when i turn the pot it doesn't get any brighter.
i love this little animation ;D ;D
 

pseudonomen137

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What do you mean its not focusing properly?

The pot isn't some magic dial to make your laser brighter. Its something to adjust power to the diode. Any time you turn up the pot, you WILL shorten the life of the diode. Up it too much and you'll find your diode's MTTF goes from 10,000 hours, to less than a second (I've found this out the hard way :-[).

In some cases, you can only turn the pot so high before the circuit maxes out and turning the pot any higher doesn't change a thing. That could be what's happening. You may also be maxing out your crystal set, or a few other things. In the end though, it all boils down to the fact that the pot is not the thing you turn to make your laser brighter - its function is much more subtle than that.
 

styropyro

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pseudonomen137 said:
Up it too much and you'll find your diode's MTTF goes from 10,000 hours, to less than a second (I've found this out the hard way  :-[).
So I must have got lucky. I modded my greenie over a year ago to the max it would let me (with a lens I can smoke black plastic, pop baloons almost instantly ) and I use it ALL the time and it still works? Do you think it might die soon?
 
S

SenKat

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You have shortened the life span - no telling by how much - it could work perfectly well for minutes, hours, months, etc....there really is no way to accurately tell.
 

Things

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so what kind of power level should this laser have, without modding or anything? just estimating? it's out of a 20mw DX laser if it helps?
 
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SenKat

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Well, most likely it is a 200mw 808nm pump diode...that is only a guess, but on the smaller versions, I am fairly certain it is a 200mw IR.
 




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