1 HN user recommended this demo1 month2020–2022score 1
Years with an HN recommendation, 2007–2026
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.
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.
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]
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]
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]
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