We’ve got to say that [Les Wright] has the most fun on the internet, at least in terms of megawatts per dollar. Just look at his new video where he turns a $30 eBay tattoo-removal laser into a benchtop beast.
The junk laser in question is a neodymium:YAG pulse laser that clearly has seen better days, both externally and internally. The original pistol-grip enclosure was essentially falling apart, but was superfluous to [Les]’ plans for the laser. Things were better inside the business end of the gun, at least in terms of having all the pieces in place, but the teardown still revealed issues. Chief among these was the gunk and grunge that had accumulated on the laser rod and the flash tube — [Les] blamed this on the previous owner’s use of tap water for cooling rather than deionized water. It was nothing a little elbow grease couldn’t take care of, though. Especially since the rest of the laser bits seemed in good shape, including the chromium:YAG Q-switch, which allows the lasing medium to build up a huge pulse of photons before releasing them in one gigantic pulse.
Cleaned up and with a few special modifications of his own, including a custom high-voltage power supply, [Les]’ laser was ready for tests. The results are impressive; peak optical power is just over a megawatt, which is enough power to have some real fun. We’ll be keen to see what he does with this laser — maybe blasting apart a CCD camera?
Styropyro did a… meme… of this about 3 years ago as well:
https://www.youtube.com/watch?v=-BeTq99LqUo
Not gonna lie all this stuff just floating around on the internet makes me nervous
You can’t have a megawatt laser, you’ll shoot your eye out!
To put things into perspective, when you shuffle your feet across the carpet and get a nasty snap on your fingertip, the energy of the spark is about 3 milliJoules. The discharge lasts for some nanoseconds, and the peak power can reach a megawatt.
A tattoo removal gun, if my math is correct, is very similar with a spot pulse energy in the neighborhood of 5 mJ.
Let’s see…what would you do with such a laser? Make not-so-enormous Swiss cheese? Pop at least small amounts of popcorn? Use a beam splitter with it to advertise your Tanning Invitational? Where’s Mitch and Chris when you need them?
Love the reference! All I need now is a big spinning mirror…
If it makes you nervous, just don’t play with the technology. For those who are comfortable, then go for it. Win Win. Finally, those that fall in-between, let the Darwin affect come into play. Simple.
Enjoyed the video. Thanks!
You are welcome!
Also agreed. This level of stuff for hobbyists has been around long before the internet was even a thing!
You used to be able to mail order plans for High voltage, pulsed power and Lasers. Ah, the good old days!
Awwww!
I was hoping it would be used to remove tattoos again!
But it does! Also the skin it is on and quite a bit of subcutaneous flesh!
“Is someone cooking pork?”
1 Million watts is a bit much. I suspect that it isn’t really 1 million watts, maybe in Chinese specs, but not in reality. This looks like around a 10 watt laser. But you don’t really need 10 watts. 4-5 watts should be able to shatter the tat particles, and let the body remove them. I use to work on 1080nm Neodymium Yag lasers that were 8 watt max. They were used for oral surgery. However crank them down to 4-5 watts, and hit a tat with it, and you can see the tat go away in about 4-8 weeks.
You might want to read up on how pulsed lasers work..
The average power is low, but the peak power is high though only for a duration of a few nanoseconds.
Q switched lasers are pulsed, so the beam is on for an incredibly short period of time. It effectively charges up and then releases a ton of power in a brief period. Because the denominator is so small, you get some medium level of Joules divided by some incredibly small time, resulting in a huge power.