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improving cheap ebay 5mW 405nm adjustable focus blue/violet laser

EliteFunk

EliteFunk

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ok, so I bought a cheap 5mW 405nm adjustable focus blue/violet laser from ebay

405nm Blue Violet 5mW Laser Pointer High Power Burning Adjustable Focus Key | eBay

and I have a few questions. I'm sorry in advance if these questions have been answered, I browsed the forums for a bit before making this post but didn't find what I was looking for, since I'm unfamiliar with the terminology I wasn't sure what to search for, but anyway. I'm wondering-
A: is it possible to safely increase the power output?
B: there is quite a bit of excess light around the beam, like a halo or something (its not from my eyes glowing in the UV light) is there a way to fix that without replacing the lens?
Finally: I know 5mW lasers aren't too dangerous when used responsibly, but since it has adjustable focus if I look at the dot at its finest point it seems a lot brighter, should I be worried about this damaging my eyes?

Also I would be interested in hearing about any modifications that can be made to this laser to spice it up a bit, I'm new to lasers, but quite experienced with electronics and I'm not too concerned if I wreck the laser in the process, it was cheap enough. Eventually I want to spend some good money on one but I want to learn as much as I can with the cheapos before I commit to spending 100s of dollars on something I don't REALLY need :P

Anyway, thanks for any advice or insight you can offer, and again sorry if this has been covered already.
 





The first thing you need is eye protection! your laser it most likely well over 5mw. so it doesn't need spicing up. the halo is prolly due to a cheap lens that's smudged. you may be able to clean or replace it.
 
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EliteFunk said:
ok, so I bought a cheap 5mW 405nm adjustable focus blue/violet laser from ebay

405nm Blue Violet 5mW Laser Pointer High Power Burning Adjustable Focus Key | eBay

and I have a few questions. I'm sorry in advance if these questions have been answered, I browsed the forums for a bit before making this post but didn't find what I was looking for, since I'm unfamiliar with the terminology I wasn't sure what to search for, but anyway. I'm wondering-
A: is it possible to safely increase the power output?
B: there is quite a bit of excess light around the beam, like a halo or something (its not from my eyes glowing in the UV light) is there a way to fix that without replacing the lens?
Finally: I know 5mW lasers aren't too dangerous when used responsibly, but since it has adjustable focus if I look at the dot at its finest point it seems a lot brighter, should I be worried about this damaging my eyes?

Also I would be interested in hearing about any modifications that can be made to this laser to spice it up a bit, I'm new to lasers, but quite experienced with electronics and I'm not too concerned if I wreck the laser in the process, it was cheap enough. Eventually I want to spend some good money on one but I want to learn as much as I can with the cheapos before I commit to spending 100s of dollars on something I don't REALLY need :P

Anyway, thanks for any advice or insight you can offer, and again sorry if this has been covered already.
Click to expand...

As was stated above... Those "5mW" 405nm Lasers from eBay
output a lot more than 5mW and are dangerous to human eyes.

Before using your Laser any further I would suggest you get
some appropriate Laser Safety Goggles/Glasses.

Your Laser is probably putting out between 30-60mW...:eek:

Modifying cheap Lasers (Pot Modding) is basically frowned upon
by the majority of the Forum and can easily turn your Laser into
a useless stick.

The halo may be as was suggested.. a smudge on the plastic lens.


Jerry

You can contact us at any time on our Website: J.BAUER Electronics
 
wow thanks for the replies, glad i decided to ask, i figured if anything a cheap ebay laser would have a lower output :s i do notice a small transparent orange spot in the center of my vision after using the laser, but it goes away after a couple minutes. I read some threads on this site about eye injuries and everything i read seemed to state that my laser is safe, but like i said i had no idea a cheap laser could have a higher output. I have safety glasses in the mail as we speak hopefully they get here soon.

as for pot modding, I know its not really a good idea, i ruined a green laser pen by pot modding it, but luckily it was only 3 bucks :P

now the lens, I do notice when i focus the beam as wide as possible there are spots on the lens, i tried to clean it with a q-tip, didnt work, so i added a VERY small amount of 99% isopropyl to the tip of the q-tip and tried again, still nothing. would it be worth the effort to replace the lens?
 
The smudges could be on a the back side of the lens or on the diode window itself.

Replacing the lens might not be all that difficult if you can get to the back of the lens. It may be held there by glue or something that you can pop off. You might be able to drop in a standard 3-element lens or something if you don't mind doing some modifications to the laser, that is if it can even fit at all.

I would suggest trying to find a way to clean the back of the lens and if that fails try cleaning the diode window. Then, if all else fails then try replacing the lens.
 
I think my "5mW" violet I got from Amazon metered at about 40mW. Of course, that was part of the reason I bought it. The DealExtreme one I got for like $18 was a little better, at 15mW.
 
thanks for the advice, i will probably try that.

also I wanted to ask if its dangerous to view the beam itself without protection? or is it just looking at the dot or diode itself that can cause damage?
 
The little $6 405nm pen I got off amazon metered at 64mW. I wouldn't be surprised if its life is going to be very low. I don;t particularly care though since I gave it away when I built my 600mW 405nm XD

The beam is perfectly safe to look at until you get to extremely high power(nothing we can attain in a hand held).

Avoid looking at the dot at anything less than 10 feet and NEVER look right at the diode.
 
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hahaha obviously never look at the diode :P

I tried cleaning the diode window and the back of lense, it helped big time but there is still some excess light around the dot. could it be reflections from the inside of the lens module? if so could i just sand it with a really fine grit to smooth out the imperfections or would that make it worse?

also I am thinking about ordering the 3 piece lens you mentioned, but im not sure what size to get, or if any of them will fit (looking on this site: https://sites.google.com/site/dtrlpf/home/glass-lenses)

again I really appreciate the help, thanks for not throwing bricks at the noob :3
 
It is fairly common for a laser to have a small amount of light bounce around inside the cavity with the lens and cause small reflections on the output. A 3-element lens may solve or reduce the reflections. If you want to try, go with the "405nm-445nm AR Coated Three Element Glass Lens" which is the first thing on the page.
 
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