Styropyro tests an eBay laser tattoo removal device and finds it is a roughly million-watt pulsed laser, powerful enough to ignite air in the beam. He had bought it hoping to salvage an Nd:YAG laser cavity.
Why Hacker News points people here: HN mostly cites it as an example of the absurdly powerful lasers sold cheaply online, and a nod to the channel's DIY laser builds.
“builds insanely strong lasers with basically salvaged junk electronics.”
Builds extremely strong lasers from salvaged electronics
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You've obviously never heard of styropyro who builds insanely strong lasers with basically salvaged junk electronics. this video
Cites itdarkenFeb 2020
“Tattoo removal tends to use ~1MW pulsed lasers (yes, megawatt).”
Cheap tattoo removal laser kit demonstrated
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Tattoo removal tends to use ~1MW pulsed lasers (yes, megawatt). The pulse is extremely short (nanoseconds), but at that power/instant-brightness it's enough to fry sensitive imaging electronics. Can also do fun things like blast holes through CDs. I'd learned about the topic the other day here ("plays" with a cheap tattoo removal kit off the web): this video
Criticalben_wFeb 2020
“whose included safety goggles are more than a little suspicious”
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More worryingly, it’s possible to buy pre-built laser etchers online that don’t come with safety glass: link And Q-switched pulse lasers for hair removal (i.e. to be aimed at your face) whose included safety goggles are more than a little suspicious: this video
JokescottlocklinJan 2020
“Dunno man you can buy some really wack lasers off of ebay”
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Dunno man you can buy some really wack lasers off of ebay: this video They were talking about this kind of particle accelerator in the 90s back when I used to hang out with accelerator physicists. Though back then it was going to be terahertz waves rather than lasers. Still got to power it with something. IMO best mad scientist weapon is something like this: link