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ArcticMyst Security by Avery

Do I need a lens?

Joined
Jan 29, 2016
Messages
11
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Hey maybe you pros could shed some... Er, light on my laser problem. I bought a cheap laser off this electronic Bay website. It is a 405nm with a cool violet colour, but the problem is it has no lens. The beam divergence is crazy, it turns into a 4 inch blob at about 10 feet away, and outside it turns into this weird star pattern with one dot in the middle and about 6 dots of purple hazy coolness surrounding it. I looked directly into the laser when it was on to see what the problem was (jk! don't ever do that.) but when I look into it, I can see its clearly just a diode, housed in a pen shaped... Uh, house. (host? Oh man..) is it worth gluing a lens inside it? How much is a small lens for this thing, and where can I get one? Or should I take it and throw it into an active volcano? My precious...
 





diachi

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Joined
Feb 22, 2008
Messages
9,700
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Hey maybe you pros could shed some... Er, light on my laser problem. I bought a cheap laser off this electronic Bay website. It is a 405nm with a cool violet colour, but the problem is it has no lens. The beam divergence is crazy, it turns into a 4 inch blob at about 10 feet away, and outside it turns into this weird star pattern with one dot in the middle and about 6 dots of purple hazy coolness surrounding it. I looked directly into the laser when it was on to see what the problem was (jk! don't ever do that.) but when I look into it, I can see its clearly just a diode, housed in a pen shaped... Uh, house. (host? Oh man..) is it worth gluing a lens inside it? How much is a small lens for this thing, and where can I get one? Or should I take it and throw it into an active volcano? My precious...


Can you give us a link to what you bought? Or a picture at least.

Could just be your eyes - 405nm is right on the edge of what most people can see, sometimes it does funky things with our eyes. I can never get it focused at a distance for that reason.
 
Joined
Mar 27, 2011
Messages
14,125
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113
If you smoke, or vape, try shining the laser in complete dark after you do it, and look at the beam rather than the dot. If you can see the beam become wider, then yes, a lens could maybe help. (Or steam up the bathroom.)

To me, what you are describing, "weird star pattern with one dot in the middle and about 6 dots of purple hazy coolness surrounding it" is kind of similar to what I see, if looking at the dot of a 405nm laser at close range.

You can also see if it's a problem with divergence, and a lack of lens, by looking at the dot on the wall, through a pair of safety goggles. (Those are definitely worth getting.)
 
Joined
Jan 17, 2011
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Sounds like there is a star filter on it. One of my eBay laser came with one. My thinking the broken up beam makes any single point <5mw. Perhaps you could post a picture.
 




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