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ArcticMyst Security by Avery

How to easily verify the power of eBay lasers? Are these trusted? How to build it?

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I want to get into some beginner laser work. I am a physics and EE major so i have some experience with circuits but i never built any projects of my own really.

I want to start out small, build a 30mW or so laser (in purple preferably but other colors are fine) which can burn paper and pop balloons. Is 30mW high enough for purple lasers to do this? I chose purple not only cause i like the color but it has a higher photon energy than any other visible laser so i would assume it can achieve burning with less current.

How exactly do you adjust the beam on a laser? Is the glass lens bendable somehow? How do i make the beam thicker or thinner?

After that I think it would be cool to make a TriColor laser but i'm not sure how to combine the beams. Anyway i think that may be a question for later.

My first questions are whether or not i can trust these lasers:

405nm 30mW Violet Laser Diode Module DIY Lab Astronomy | eBay

I just searched ebay for "405nm Laser module," and i am not sure if that has a driver circuit on it or not, it looks like it does since it has some PCB attached but im not 100% sure. If i wanted to build my own driver circuit where would i go to learn how to do that? and are all driver circuits used for all wavelengths? I assume since all the driver circuit does is regulate the current it can be used on any diode.

second, how exactly can i verify the power output of my laser without a 100+ dollar tool.
 
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First off a 30mw laser would not burn paper maybe pop a balloon if your lucky. Around 1W 445nm laser can ignite white paper. Message the Ebay seller and ask if its a true 30mw 405nm.
 

gozert

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If you want to learn about building your own driver, you may want to take a look in the Drivers, Test-load, Power Supply, & Batteries section.

For adjusting the beam width on a laser, you simply turn the focusing knob one way or another. Inside the focusing knob is a lens that screws closer to, or further away from the lens.

What I would suggest though is picking up a simple and cheap host from one of our members here and putting a DTR module in it with the driver already installed. It's a fun first project, and doesn't require more knowledge than being able to solder two wires together.

30mW is definitely not enough to do any decent burning. You'll need to go a lot higher for that. You're probably best off picking up a 1.8W module with driver and G2 lens from DTR (link) and a 501B host from Mrcrouse (link).

The module costs about 75$ and the hosts start at 20$ or so, shipping excluded.

Why did I choose 445nm (blue), and not 405nm (purple)? Because you can barely see 405nm even at high powers, and the 445nm will do the job just as good for a bit less money. You can use the 800mW module he offers too, but why not get 1W more power when the price is the same?


Regardless of what power you're going to get, be sure to get yourself a good pair of safety goggles. Eagle Pair® 190-540nm Standard Laser Safety Goggles
 
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APEX1

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I want to get into some beginner laser work. I am a physics and EE major so i have some experience with circuits.



I'm having a little trouble with that first statement you made about what your going to school for, and your asking for help in something you should almost be a master at.. my brother has his phd in physics. to be more accurate he is a theoretical physicist.. What I'm getting at is you should have already had your teachings in electronics, ect... Not trying to blow your spot up but I smell something fishy. Or I'm just crazy!!!!:drool:
 
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