Dangerous tattoo remover from eBay is a MILLION watt laser
Why Hacker News recommends it
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.
What it is
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.
Recommended by 1 HN commenters across 1 different months, 2020 to 2022.
What Hacker News said
Recommends adamsmith143 · 2022-09 · on “Neutralisation of cockroaches with laser automated by machine vision”
You've obviously never heard of styropyro who builds insanely strong lasers with basically salvaged junk electronics. [this video]
Cites darken · 2020-02 · on “Tip: Don't record laser tattoo removal (2019)”
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]
Critical ben_w · 2020-02 · on “Lasersaur – open-source laser cutter”
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]