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Beam and dot problem: Beam expands, dot is as big as my hand after 30

hoo7h

hoo7h

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Hi

I have just put my laser together, and I saw this problem
I am using M140 diode and G-2.


After 30 cm from the laser, the beam expand, and the dot gets very very big and the laser doesn't even pop a balloon or light a match.

I am sure that the lens is not upside down.


Here is what happens when I focus it, first a big square, then it gets smaller ,then it becomes dot surrounded by blue light, looks like a line but wider, when I focus it more it turns to a big circle and it gets bigger when I focus it more.



What is wrong with it ??
 
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Blord

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It looks not a problem to me. You need to focus the dot for popping balloons. With focussing I mean to the smallest dot.
 
hoo7h

hoo7h

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Blord said:
It looks not a problem to me. You need to focus the dot for popping balloons. With focussing I mean to the smallest dot.
Click to expand...

I don't get a small dot except after 5 cm from the laser, anything more there is no focused dot, and the beam expand too.
 
Blord

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Did you press the diode enough into the module ? The G2 lens must sit very close to the diode or else you won't reach focus with it.
 
hoo7h

hoo7h

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Blord said:
Did you press the diode enough into the module ? The G2 lens must sit very close to the diode or else you won't reach focus with it.
Click to expand...

I bought it with its module pressed already
 
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Blord

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Can you take pictures of the lens and the RAW output of the diode without lens ?
 
hoo7h

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Here is how the lens look like
W4Ua6.jpg

xhxNW.jpg

0B7tg.jpg


This is the diode
v1UoL.jpg

There is some shiny metal thing beside the center

Here is a beamshot with the lens focused (best focus I saw)
xH6x0.jpg

It doesn't really looks like a round circle but this is what my iphone gets, it looks like a wide line with a dot in the middle, look at the beam expand, this is not from the camera it does expand like this


The is how it looks without the lens
0FqEt.jpg
 
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Blord

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Your RAW output looks very different. It should look like this,
p1018363.jpg

I am afraid your diode has turned into a LED.
 
hoo7h

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Blord said:
Your RAW output looks very different. It should look like this,
p1018363.jpg

I am afraid your diode has turned into a LED.
Click to expand...

Oh shit what do you mean by turning to a LED ?
Am I screwed ?
 
Blord

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LED mean light emitting diode. It doesn't emit laser light anymore, just ordinary light.
 
hoo7h

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Blord said:
LED mean light emitting diode. It doesn't emit laser light anymore, just ordinary light.
Click to expand...

Why does that happen ?, is it because of any mistakes by me ?, do I send it back to the seller ?
 
grainde

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Hey Blord are you sure? He still has a narrow collimated beam of light coming out of his laser. If it had LEDed wouldnt it be like a weak LED ie without a stong beam that you can easily photograph?

Maybe he has some dirt or debris on the diode window? Have you also tried turning the lens around? FYI it should be set up like this to work, with the optic close to the diode. :beer:

Edit: Does it still burn when focused to a small point close to the laser and does it appear nearly as bright, visually, as it did before? You could test this at night (outdoors) and compare the beam with what you remember. It wont give you any idea of power but it should help you discern whether it has LEDed.

Edit 2: I think I saw something like this before, when someone damaged the diode window. I think they actually burnt or partly melted it...?:thinking: Ill try to find it.
 
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hoo7h

hoo7h

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grainde said:
Hey Blord are you sure? He still has a narrow collimated beam of light coming out of his laser. If it had LEDed wouldnt it be like a weak LED ie without a stong beam that you can easily photograph?

Maybe he has some dirt or debris on the diode window? Have you also tried turning the lens around? FYI it should be set up like this to work, with the optic close to the diode. :beer:

Edit: Does it still burn when focused to a small point close to the laser and does it appear nearly as bright, visually, as it did before? You could test this at night (outdoors) and compare the beam with what you remember. It wont give you any idea of power but it should help you discern whether it has LEDed.
Click to expand...


Yes it does burn black stuff very fast, and it burns white paper after few second, but from a close distant, 1-10 cm
 
Blord

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It could be dirt on the diode window. You need to clean it.
If it doesn't work then the diode must be decanned. That will be a hard job because the diode is already in the module.
 
BShanahan14rulz

BShanahan14rulz

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hoo7h said:
This is the diode
v1UoL.jpg

There is some shiny metal thing beside the center
Click to expand...

I think this is where the problem lies. Usually the window has an even coating, with sometimes a tiny "burn" mark where the beam passes through. Does your diode have this window with the gold-ish (I think it's goldish, right, folks?) coating?
 
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