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Ring around dot?

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OahJaeh

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Hello,
I have recently purchased a blue laser from ebay for 70$. It has worked perfectly until now... Whenever I use it, it has a large ring around the dot, I've used an air duster to clean out the diode and lens but nothing has worked.

Please help!

Picture of dot: Imgur: The most awesome images on the Internet
 





OahJaeh said:
Hello,
I have recently purchased a blue laser from ebay for 70$. It has worked perfectly until now... Whenever I use it, it has a large ring around the dot, I've used an air duster to clean out the diode and lens but nothing has worked.

Please help!

Picture of dot: Imgur: The most awesome images on the Internet
Click to expand...

I would say that it could be from any internal reflections from the host but since this hasn't happened before I'd rule that out. My guess would be the acrylic lens wearing down. But if you got really lucky and received a glass lens (doubt it) then I'm not sure. Try using a different lens to see if you notice a difference or even try running the laser without a lens to see if you can find a problem.
 
ElectricPlasma said:
I would say that it could be from any internal reflections from the host but since this hasn't happened before I'd rule that out. My guess would be the acrylic lens wearing down. But if you got really lucky and received a glass lens (doubt it) then I'm not sure. Try using a different lens to see if you notice a difference or even try running the laser without a lens to see if you can find a problem.
Click to expand...

Well, without a lens it looks like a flashlight. The laser just came in yesterday. I dont have another lens.
 
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OahJaeh said:
Well, without a lens it looks like a flashlight. The laser just came in yesterday. I dont have another lens.
Click to expand...

So, you just got it? From the OP, I got the impression you've had it awhile. It looks like a bad lens to me. If it is indeed a 1 watt laser and has an acrylic lens, that would be your problem. If it came from China, it is too much money to send it back, but if you used PayPal to pay for it, I'd open a dispute over it's failure to work as advertised and only send it back if the seller pays the shipping. Either way, you should be able to get your money back.
 
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So, there wasn't a ring around the dot before? Some splash is normal. It however depends on the diode, lens, and lens holder.

You might want to post a photo of the output without the lens. It should help with diagnosis. :)
 
It looks like the ring is there even without the lens. That might implicate the diode window. Have you tried to clean the window with 99% isopropanol and a lint free cloth?
 
If it actually looks like that on a matte surface that's not good news. I can't really tell what the finish on that door is though, but it could be the cause of the ring since it looks like it's -only- on the door surface and not even on the doorframe.

Besides that ring artefact the output without a lens looks good - splotch of light that is brightest in the center with no odd dark or bright areas.

If unsure just take the picture again with the laser rotated 90 degrees - if it's caused by the door the ring will still be there, if it's caused by the laser it should be to the side instead of the top.
 
Benm said:
If it actually looks like that on a matte surface that's not good news. I can't really tell what the finish on that door is though, but it could be the cause of the ring since it looks like it's -only- on the door surface and not even on the doorframe.

Besides that ring artefact the output without a lens looks good - splotch of light that is brightest in the center with no odd dark or bright areas.

If unsure just take the picture again with the laser rotated 90 degrees - if it's caused by the door the ring will still be there, if it's caused by the laser it should be to the side instead of the top.
Click to expand...

Picture horizontally: Imgur: The most awesome images on the Internet
 
paul1598419 said:
It looks like the ring is there even without the lens. That might implicate the diode window. Have you tried to clean the window with 99% isopropanol and a lint free cloth?
Click to expand...


Where can I find isopropanol or in what products?
 
It's difficult to see which side of the window it is on. If it is on the outside, clean with 99% isopropanol. Don't use a smaller percent as it will contain water and other impurities. I wouldn't use denatured or other types of rubbing alcohol. You could use lab grade ethanol, but that is very expensive and also difficult to obtain.
 
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ElectricPlasma said:
isopropanol = rubbing alcohol, any department store and probably pharmacies
Click to expand...

Check the purity though, department store stuff sometimes is only 70% or has other additives which leave residue on optics. Ideally you want lab grade Isopropyl for optics.

Looks like the artifact may be from a little glue having seeped out of the window seal on the diode, going by OPs picture of the window.

OP - careful not to get dust or dirt on that diode window.
 
paul1598419 said:
It's difficult to see which side of the window it is on. If it is on the outside, clean with 99% isopropanol. Don't use a smaller percent as it will contain water and other impurities. I wouldn't use denatured or other types of rubbing alcohol. You could use lab grade ethanol, but that is very expensive and also difficult to obtain.
Click to expand...

What do I do if its on the inside?
 
OahJaeh said:
What do I do if its on the inside?
Click to expand...


Either live with it (Or get a refund! :p) or send it to someone to remove the window and can that the window is attached to - for something that cost $70 the latter option may not be worth it.
 
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