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New Member, new and firsttime Sanwu Pocket owner, I have question about fixing beam reflecting/leaking beyond the dot.

TrevorWesley

New member
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Feb 22, 2022
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Hey guys! My name is Trevor, I recently received my first Sanwu laser, s 492 Cyan 100mw. It’s really awesome! I just have a question about the beam/light reflecting from the inside and spreading a bit beyond the dot. I want to know if anybody has any ideas about modding the lens for safety reasons. I don’t want the bleed of the laser to go somewhere I am not aware of like someone else’s or my own eye. I thought of maybe paint, tape… something but I don’t want to cheapen the laser at all especially since it is so well made. If you guys have any ideas I’d appreciate the feedback! Thanks! -Trev
 





Seems to be an issue not just for you but for this guy too. Look at Beam Specs in his post.

 
Clean the dust window or lens and if needed add a shroud, such as a rolled up tube of paper to block any wide angle diffuse aberrations.....also a longer focal length lens can help in some cases, but cleaning the dust window would be a good 1st step, I use Zeiss pre moistened lens cloths in the foil packs along with a q-tip.

 
Welcome to the forum! :D


I have the 488nm version of the Sanwu pocket and it does have a bit of the same problem. I have tried cleaning the lens and it still has a bit of splash to either side of the dot:



sanwu488.jpg




It does seem to do it a bit more than the other lasers in my collection. It might be the shape of the beam and aperture that it's always gonna hit the side of the aperture a little bit on the way out and cause that splash pattern.

Can see it quite a bit in this picture, above the second from left dot:

DSC-0734.jpg




Edit: Added some extra pictures here. I think it's hitting part of the host that holds the adjustable lens at the front.


Without the front lens at all:

sanwu4883.jpg



Here I collimated it using an old camera lens and it has far far less of that splash:

sanwu4882.jpg
 
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That looks like a wide angle aberration, when you want to take a pic like that, try a rolled up length of black cardstock paper or construction paper to absorb the aberration and give you a cleaner beam.

This also eliminates that annoying lens flair when taking a picture looking back towards your lasers output.

SANY6440.JPG
 
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Firstly, welcome to LPF!

I think one way to reduce the splash is to switch to a more restrictive lens, like a 3-element lens? Of course if you wanted a perfect beam profile you can us a spacial filter, but that is impractical for a handheld. The splash around the beam is normal for many diodes, and low enough power density.
 
Firstly, welcome to LPF!

I think one way to reduce the splash is to switch to a more restrictive lens, like a 3-element lens? Of course if you wanted a perfect beam profile you can us a spacial filter, but that is impractical for a handheld. The splash around the beam is normal for many diodes, and low enough power density.
Word! Thanks. Do you know if Sanwu lenses work for the pocket? Thnx!
 
Hey guys! My name is Trevor, I recently received my first Sanwu laser, s 492 Cyan 100mw. It’s really awesome! I just have a question about the beam/light reflecting from the inside and spreading a bit beyond the dot. I want to know if anybody has any ideas about modding the lens for safety reasons. I don’t want the bleed of the laser to go somewhere I am not aware of like someone else’s or my own eye. I thought of maybe paint, tape… something but I don’t want to cheapen the laser at all especially since it is so well made. If you guys have any ideas I’d appreciate the feedback! Thanks! -Trev
I've only gotten big wings with dust or cheap lasers. I'd do like the other suggest and try the cleaning, then build another 2 or 3, so I had one to mess with while I was figuring out the len's for this one.
 


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