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Line beam with Senkat's GB diode!?

zerafiel

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Another in the dark.
 

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zerafiel

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End result. left most gouge is at lower power and the right 2 gouges were the smoking ones. gonna pump more current into the diode!
 

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Gazoo

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;D Glad you are having fun..I found 160ma's to be the sweet spot for burning...no pun intended. :p
 

zerafiel

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Gosh, I'm forgoing sleep to burn chocolate. I'm still underdriving my diode. Gotta punch a hole through that slab of choc before i sleep.

Funny how the line disappears at higher powers. Maybe it is still there cept it is too weak.

How do we calculate the power output from the input current?
 
S

SenKat

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I THINK what has happened here, is the diode in wuestion may be lasing at a higher threshold than some others...a typical beam spec like that is created when there is not enough juice running into the diode for the entire emitter to activate...I hope that makes sense ? Since the emitter is amost microscopic, and going through high powered optics at close range - it dramatically magnifies the end result....
 

zerafiel

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I think you are right. My voltage drop was too big and hence my diode was underpowered. Makes sense and my diode is burning great now. Burnt chocolate and electrician tape do not a good smell make.

Thanks again for the clarification.
 

Benm

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I think you're onto something here, see photographs. The line comes from the diode, not the aixisz lens, as it doesn't rotate with the lens.

Just above threshold, 40 mA, you can clearly see the line. At higher power it's still there, but the dot gets so bright it's hard to spot a 120 mA and near invisible beyond. I've also indicating the resulting voltage across the diode at various currents, this goes up to about 2.75 volts at 160 mA.
 

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chimo

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Mine do this as well. My "Glowtorch" type Red Laser also has these artifacts. Probably due to the light source being linear and not round.
 

zerafiel

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Wow, I gotta commend you on your photography. My cheap digital camera is unable to capture the lines like you did. That was exactly what my beam looks like!

But I think Greg's explanation makes the most sense, at least in my case.

But you guys might be right too in that it might be an emitter problem as well, since his beam does show visible saturn rings at higher powers.
 

zerafiel

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How sensitive are bare laser diodes to magnets? eg those with strength to the rare earth magnets found on DX.
 

naplam

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I have the same "saturn" pattern on my GB diode at low power (on both i've tried so far), I think they're all like that. Anyway, i've been trying to burn matches and i can't get them to ignite. I focused the aixiz module properly and i went up to 180mA current. Maybe I need to point it more carefully so it's on the same spot for a couple of seconds... i don't know. What do you guys think? i'll try to put it into a better housing (flashlight or whatever) so i can aim better.
 

Gazoo

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What kind of matches...safety matches, or the paper ones with white heads???
 

naplam

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Gazoo said:
What kind of matches...safety matches, or the paper ones with white heads???
Regular matches. Safety matches i guess, not the ones with white heads.
 

Gazoo

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The match should light easily from a couple feet away. The beam does need to be focused as well as steady...no movement.
 

naplam

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Ah I finally did it! it was just a matter of aiming accurately to the head of the match for a couple of seconds. :) :) :)
 




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