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ArcticMyst Security by Avery

M140 Laser Diode Does Not Burn

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May 26, 2011
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I'm making a box build with the driver set at 480mA which I was told would give me about a 325mW output. I had it all connected and the diode turns on and is not very bright (which is expected for a blue). However, even when focused to a small point, it does not burn. It doesn't even get black electrical tape or a match (with or without a black dot) any more than the slightest bit warm. I am using an AiXiZ 3 element glass lens. I also tried another driver I have that's set at 200mA just to see if it was the driver. I also did nothing; even at that current it should have done even a little something to something black. What am I doing wrong?
 





Blord

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Show us the raw output of the laser without the lens. I am afraid your diode has LED.
It is still giving light but it isn't lasing anymore.
 
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What's that and what causes it? I got it last week from DTR and have barely used it.
Is this what you mean by raw output?
0419131754.jpg
 

Blord

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It should look like this. Static electricity can kill a diode or sudden rush of current from the driver if it isn't discharged yet.

p1018363.jpg
 
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May 26, 2011
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Your picture is from a dark room though, mine was in a lit one... If that matters... I always assumed a killed LD would just not turn on at all. Is there any way to know for sure if I need a new one or not?
 

Blord

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It is not my picture. That is an example of an output from a good diode.
We need to see the pattern in the output. Your picture doesn't show that clearly.
 

DTR

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It is either LED or under the lasing threashold. Can you give details on your setup? Driver, powersource, maybe a picture of it all.
 
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I'm now using two 14500s in series with an X-Drive at .5A. I was using a test power source before and actually only putting .2A through it (silly me). Now it has the full amount going through it from the batteries. It's much brighter than before but still does not burn anything. Am I maybe not focusing it right or something?
 
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Oct 14, 2011
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@ .5A it should be lasing and burning. So i think your diode has LED'D. Which is a shame. Try to up the current to 1A to be sure it is dead. But from whati see it has LED'D.

Greetings,,

EDIT: does the about still look the same as your last picture at .5A? If it looks like blord's it could be a focussing problem.
 
Last edited:
Joined
May 26, 2011
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I can get it to a fine point but there's unfocused rings of light around it. The batteries just got low so hopefully that was the problem. They're charging now. I'll upload a picture when they're done.
 

B33M

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Aug 11, 2011
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i had a blue do this and it was melted glass in the diode i broke the window out and it was fine
 
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It's much brighter than before but still does not burn anything. Am I maybe not focusing it right or something?
How small can you make the dot? I have a 1.5w and it doesn't burn good unless the dot is <4mm. I also recommend getting a better lens...
 

DTR

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I'm now using two 14500s in series with an X-Drive at .5A. I was using a test power source before and actually only putting .2A through it (silly me). Now it has the full amount going through it from the batteries. It's much brighter than before but still does not burn anything. Am I maybe not focusing it right or something?

If it got brighter take another picture of the raw output if you can. Can you give an idea what the "test power source" you were using is?
 




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