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How I got my laser eye injury

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Re: How I got my laser eye injury

#231

Post by SXX »

talldayo wrote: post #77
NathanielBaking wrote: post #61

Safety guys always ruin the fun. I was in the Marine Corps and every time we got to test some new piece of gear the safety officer was like "No, you can't live fire it off the flight deck of the ship" or "No, not here, that village is down wind of the dust you will kick up when it goes off." No, that has a kill distance of 6 miles, you have to fire it into a hill." Blah, blah, blah. So after I got out I joined the Na…

It's all fun and games until you walk in front of a live AESA radar and sterilize yourself.

Is it scientifically proven though? If it that powerful wouldn't it cook your brain as well?

Re: How I got my laser eye injury

#232

Post by hatsunearu »

not really related, but people say you shouldn't look directly at the sun.

I don't understand why having the sun in your field of view at all isn't dangerous then. wouldn't that cause the sun to burn a hole somewhere inside your eyeball that isn't the direct center?

Re: How I got my laser eye injury

#233

Post by dreamcompiler »

radlad wrote: post #209
cowthulhu wrote: post #164

Earlier quoted context omitted.

Are lasers typically able to reflect off of surfaces that diffuse light (ie drywall)? I’m totally ignorant when it comes to laser safety, apologies if this is a stupid question .

Surfaces may produce diffuse or direct reflections (or more commonly, a mixture of both) for any light source. If you can see it, it's being reflected.

And even if you can't see it. You won't see a spot from an IR laser while it's burning the hell out of your retina. Which is why many (but not all) IR lasers co-produce a visible spot so you can see where the dangerous beam is.

Re: How I got my laser eye injury

#234

Post by ziofill »

DannyBee wrote: post #17

So I laser weld, and beyond my own PPE, interlocks (gun won't fire if it's not touching metal, etc), the most important part of the whole setup is laser safety curtains. Because it's a 2500 watt laser, if i didn't have laser safety curtains , the relections/etc could very easily blind someone at a fairly long distance. The NOHD (nominal ocular hazard distance) is something like 10km (2500 watt laser, 0.06mm spot size…

What are the curtains made of? I’m surprised 2500W on 0.06mm don’t just go through like there’s no curtains

Re: How I got my laser eye injury

#235

Post by bryceacc »

franciscop wrote: post #111

I've touched all sorts of things in my "Maker" years, but one of the things I'm never going to touch by far is lasers. I know how bad they are, and I also know how woeful unqualified I'm for messing with lasers. Heck, I've even left a couple of dancefloors in clubs that I heavily suspected were firing actual lasers at the people, wonder how many of those were actual lasers vs light pointers and how many people got un…

Last year I went to a karaoke dance floor club thing in NYC k-town and I saw literal burn marks on the wall. A spinning laser disco thing continuously traced across the burn mark. I got our group the hell out of there but they only agreed to leave because it was too loud

Re: How I got my laser eye injury

#236

Post by dekhn »

justin66 wrote: post #124
dghughes wrote: post #57

Earlier quoted context omitted.

At a casino where I was a slot tech we used fiber optics that went into a fiber converter module and then RJ-45. Often I would look at the ends of the fiber connectors to see if they were lit or if the light looked odd. They were quite low in power but I'm surprised at myself that I didn't think of the risk. edit: optics not options

Some scientists used to look at the beam emitter to adjust the aim of old particle accelerators. The story I heard was that some of them eventually developed cataracts as a result. Come to think of it, with today's medical technology that's a lot less awful than punching holes into your retina with a laser, but I think the result back then was eventually blindness.

I met a scientist who looked into a particle accelerator; it was intention, part of a self-experiment to establish whether high energy particles can cause scintillations in the eye. In his case he very carefully calculated how to get a safe dosage.

On the other hand there's https://en.wikipedia.org/wiki/Anatoli_Bugorski

Re: How I got my laser eye injury

#238

Post by talldayo »

SXX wrote: post #231
talldayo wrote: post #77

Earlier quoted context omitted.

It's all fun and games until you walk in front of a live AESA radar and sterilize yourself.

Is it scientifically proven though? If it that powerful wouldn't it cook your brain as well?

If the radar is located on the ground, the chances are it's consuming enough energy to cook a turkey from the inside-out.

Re: How I got my laser eye injury

#239

Post by amluto »

cyberax wrote: post #183
amluto wrote: post #44

Earlier quoted context omitted.

> custom infrared -> green laser Nd:YAG lasers always creep me out. I worked in a lab that had an Nd:YAG with two janky doublers: 1064 -> 532 -> 266 nm. The output energy was supposed to be a few mJ (IIRC), but it was basically zero. So the students operating it took off the second doubler and fired it at a bookend. Nothing (well, nothing visible). Took off the first doubler. After investigation, the zapping sound wa…

> (Okay, 233nm is probably worse, but the available energy with a setup like this is much lower.) How do you get 233nm lasers?!?

Excellent question. You frequency-double 532nm and make a typo. I meant 266nm.

There are crystals that have nonlinear responses to high electric fields, and if you hit them with enough laser light, some of it comes out at half the wavelength. A lot of it also comes out at the original wavelength. Most 532nm lasers work like this, but other input wavelengths are possible, like starting at 532, doubling again, and getting 266nm.

This was a long time ago, and it wasn’t my project, so it’s possible it was slightly different, but I definitely remember the 532nm stage. And 266nm sounds credible for what the group was trying to do with the laser.

Re: How I got my laser eye injury

#240

Post by llm_trw »

notelectronic wrote: post #119
DannyBee wrote: post #17

So I laser weld, and beyond my own PPE, interlocks (gun won't fire if it's not touching metal, etc), the most important part of the whole setup is laser safety curtains. Because it's a 2500 watt laser, if i didn't have laser safety curtains , the relections/etc could very easily blind someone at a fairly long distance. The NOHD (nominal ocular hazard distance) is something like 10km (2500 watt laser, 0.06mm spot size…

I get laser safety curtains, but what do you do for reflections off the ceiling? Asking because our makerspace was recently donated a fiber laser welding unit and we don’t yet know best practices for not blinding our membership short of building a completely enclosed separate room for it with door interlocks.

>we don’t yet know best practices for not blinding our membership short of building a completely enclosed separate room for it with door interlocks.

That is the only way to not blind your membership.

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