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Sanwu challenger 800mw strange beam

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Fungusamongus

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I have a sanwu 800 mw challenger - have had it for a few weeks. Looked great at first but the beam recently weakened (at all mode settings) and there are two strange artifacts. First, the "dot" is no longer a dot. It is like a dot surrounded by two crescents - there are three separate "lobes" of light. Additionally, there is a large dimmer circular halo surrounding the dot that wasn't there before. This effect is not due to the lens as I have tried both a G2 and G7 lens and the effect is still there. Overall, it is about half as bright as my 300mw 405nm challenger.

Any ideas what is going on?
 





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dden4012

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Fungusamongus said:
I have a sanwu 800 mw challenger - have had it for a few weeks. Looked great at first but the beam recently weakened (at all mode settings) and there are two strange artifacts. First, the "dot" is no longer a dot. It is like a dot surrounded by two crescents - there are three separate "lobes" of light. Additionally, there is a large dimmer circular halo surrounding the dot that wasn't there before. This effect is not due to the lens as I have tried both a G2 and G7 lens and the effect is still there. Overall, it is about half as bright as my 300mw 405nm challenger.

Any ideas what is going on?
Click to expand...

Ask Podo or email Sanwu directly.
 
Razako

Razako

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Can you post pictures? Also saying what wavelength the 800mw challenger is would be helpful.
 
BobMc

BobMc

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Any chance you put the lens in backwards? :thinking:
 
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dden4012

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Podo is the Sanwu guy on the forum. He would end up dealing with the issue though private messages on the forum. Might as well just email Sanwu. Just reply to the email with the tracking you received.
 
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Fungusamongus

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Ok - it is 405nm. Hang on - I'll upload a photo. I am sure sanwu will figure it out but I am curious - I am not super knowledgeable but I read somewhere about diodes sometimes "switching modes" or something like that.
 
ElectricPlasma

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Fungusamongus said:
Who is podo? Sorry - I am new here.
Click to expand...

Podo is a member here from Sanwu, not sure if owner or just employee.

Laser Pointer Forums - Discuss Laser Pointers - View Profile: Podo

You may have a weird beam mode, does it look like any of these?

800px-Hermite-gaussian.png


Sounds like you're laser might be running TEM02 or similar, but I hardly know much about beam modes at all only what they are.
 
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Fungusamongus

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I am trying to post a picture of the laser dot here - hope this works.
 

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Fungusamongus

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Looks like the image labeled "tem 20" or "tem 2". Is this likely to be a permanent thing or do these diodes switch back and forth?
 
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BobMc

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By that picture the lens isn't in wrong.

Not what your going to want to hear but I've led'ed diodes before and that's what it looked like. Sorry. :(
 
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Fungusamongus

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What do you mean by "led'd a diode"? It is still emitting collimated light - the shape has changed and the power dropped quite a bit.
 
BobMc

BobMc

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Fungusamongus said:
What do you mean by "led'd a diode"? It is still emitting collimated light - the shape has changed and the power dropped quite a bit.
Click to expand...

Hopefully someone can explain it better than me. It's when a diode burns out it drops 80% of its power still works a little, mine produced a spot very simular to that. Hopefully I'm wrong but if not hopefully Podo can help. Still hoping I'm wrong but~~~~~~ :thinking:

Edit, man, there was a lot of hopefully's there. :)
 
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CynicalBrad

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Don't think I've ever seen nor heard of single mode diodes mode hopping. That is mostly a gas and DPSS thing. Unfortunately that does look led'd. It is when the die takes damage (these are being pushed hard) and the output loses coherence. When this happens, the output drops drastically and it will no longer focus properly. If it were the diode window, rolling the laser while on should cause a change in output as it rolls. These 405's are very well known to die for seemingly no reason at all. If anyone has ever had a diode mode hop, please say so.
 
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