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Does anybody know why my laser suddenly started changing shapes??? And how to fix it??? EDIT: I pulled off cap today and I don't know what to do next.

Dragon Slayer

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CurtisOliver

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This is your laser shifting transverse mode.
DPSS lasers are known to shift to TEM01 from TEM00 and is perfectly normal on the odd occasion. Usually temperature affects the mode of a DPSS. If your laser does this all the time however then it could be faulty.

Edit: Do you notice it more after a cold start, or after continuous usage?
 

GSS

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Is that a scratch on the side of the tip?
 

CurtisOliver

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The fact that he mentions it changing shape suggests mode shifting rather than a permanent defect on the lens. The odd cut of shape is just due to beam clipping.
 

GSS

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Oh I believe you on the mod hopping, but it looks like a pair of pliers were put on the aluminum tip??
 

CurtisOliver

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Oh, I see now. Sorry, it does look like he may of tried taking of the cap at some point.
 

Dragon Slayer

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This is your laser shifting transverse mode.
DPSS lasers are known to shift to TEM01 from TEM00 and is perfectly normal on the odd occasion. Usually temperature affects the mode of a DPSS. If your laser does this all the time however then it could be faulty.

Edit: Do you notice it more after a cold start, or after continuous usage?
I notice it more after a cold start
 

Dragon Slayer

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Oh I believe you on the mod hopping, but it looks like a pair of pliers were put on the aluminum tip??
Yes I did try to get the cap off, it was unsuccessfull, but I noticed it before so today I tried to pull the cap off.
 

CurtisOliver

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This is perfectly normal then. The laser is simply mode hopping. The KTP crystal inside likes warmth. Have you taken the endcap off at any point, as as diachi pointed out. The divergence looks too high.

Edit: Ok, thanks. How is the dot size at a moderate distance?
 

Dragon Slayer

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This is perfectly normal then. The laser is simply mode hopping. The KTP crystal inside likes warmth. Have you taken the endcap off at any point, as as diachi pointed out. The divergence looks too high.

Edit: Ok, thanks. How is the dot size at a moderate distance?
It is around 1,5 cm.
 

Dragon Slayer

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It is around 1,5 cm.
This is perfectly normal then. The laser is simply mode hopping. The KTP crystal inside likes warmth. Have you taken the endcap off at any point, as as diachi pointed out. The divergence looks too high.

Edit: Ok, thanks. How is the dot size at a moderate distance?
But is there any way to fix it??? Because it just shows shapes every time.
 




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