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How I got my laser eye injury

funraniumlabs.com

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Re: How I got my laser eye injury

#181

Post by hinkley »

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 had a friend, “Kevin” who got picked as a lab assistant for a guy making one of the first violet, and IIRC, picosecond lasers. It’s frickin’ laser beams so of course I had to ask way too many questions. They probably should have been using curtains but if they were he never said, and I’m sure laser safety has evolved with the wattage and commercialization, whereas this was a static benchtop system.

There were lots of mirrors and prisms and they has to calculate refraction off of them and stick carbon blocks everywhere that light transmission was less than 100% efficient so that no light could escape the system except via the target.

Re: How I got my laser eye injury

#182

Post by rtkwe »

kqr wrote: post #179
N_A_T_E wrote: post #109

I worked in a laser lab for a few months early in my career. After the safety training I fear lasers getting near my eyes in situations most people don't care about. I even look away from barcode scanners at grocery stores. Sometimes I wonder about lidar being shot in all directions from those self-driving cars around SF.

Wait, are barcode scanners lasers? I've always thought of them as red lamps because their cone spreads out so widely quickly.

It's a scanning dot moving fast enough to appear as a cone.

Re: How I got my laser eye injury

#183

Post by cyberax »

amluto wrote: post #44
gus_massa wrote: post #22

Earlier quoted context omitted.

I worked for a few weeks in a class with a custom infrared -> green laser. The teacher were very hard about glasses, how to crouch looking away from the laser table, close the door and a few more security measures. And later, I had a 5W (0.5W?) green laser at 3 yards pointed at me [1] with some optical equipment bolted to the table in the middle so there was (almost) no possibility that it hit me. The story sounds re…

> 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?!?

Re: How I got my laser eye injury

#184

Post by hinkley »

convolvatron wrote: post #134
DannyBee wrote: post #127

Earlier quoted context omitted.

Ideally you have an enclosed area with interlocks. All of the laser welders support it (and it's the standard way). They make and sell mobile ones that can be pushed around. See, e.g., https://lasersafety.com/barriers/rigid-barriers/ for some examples (I don't know these folks, they just have helpful pictures/listings of kinds of things that exist) If you can't do this, you do need to panel or curtain the ceiling or…

I tig. wear a helmet and have to buy argon every year. this seems like a huge hassle in comparison. is there that big a difference in quality and or range of processes that make it worth it?

I know one of the reasons we wanted pico-second and shorter pulsed lasers is that they can cut material with little to no damage of the neighboring material. There was a demo that I read about when this was all brand spanking new research, where they claimed that a laser scalpel causes no heat damage to tissue outside of a cell’s breadth from the contact point.

Re: How I got my laser eye injury

#185

Post by cyberax »

ta988 wrote: post #16
jmclnx wrote: post #15

One thing I learnt, different glasses for different type lasers, who knew :)

That and different glasses depending on how you use that laser... Because some lasers can do variable wavelength.

Dye lasers are the worst. You now have _two_ (or more) wavelengths to shield against. Bonus points if one of them is in IR.

That's probably how I got my eye damage - a small hole in the retina of one eye.

Re: How I got my laser eye injury

#186

Post by rtkwe »

ta988 wrote: post #99
amluto wrote: post #45

Earlier quoted context omitted.

I’ve seen some references to the universal laser glasses: Apple Vision Pro!

No, the cameras would probably not survive laser exposure beyond a cat toy pointer level power (and even then I wouldn't bet long exposure of those).

They'd still protect your little human eyes. If you wanted to use them as safety glasses normally you'd want their cameras to be easily replaceable but they would function as safety goggles for short periods until the camera caught a stray beam.

Re: How I got my laser eye injury

#187

Post by rtkwe »

WarOnPrivacy wrote: post #75
fabian2k wrote: post #58

Earlier quoted context omitted.

Because if you want to cover all possible lasers you'll block out the visible spectrum as well and won't see anything.

You can get some overlap tho. I have 520nm goggles that tone down 465nm.

That's mostly because it's tough to get a perfect notch filter in the visible spectrum but you'd never want to use the 520nm with a 465nm unless it was low enough power the fuzzy edge of the filter knocked it's power down enough to be safe.

Re: How I got my laser eye injury

#188

Post by pflenker »

madjam002 wrote: post #175
dmd wrote: post #28

I'm not entirely sure, but I suspect my Hole In My Eye[0] came from being 30 years old (I'm 46 now) and saying "look, this laser pointer is so low power, I can shine it in my eye to no ill effect!". [0] https://dmd.3e.org/a-hole-in-my-eye/

One of the things I hate most in tourist hotspots these days are the people selling high powered laser pointers, normally selling them to kids, and they are shining it at their faces, in the faces of others, and at the neighbours. I swear they never used to be so commonplace. Having worked nightclub lighting a long time ago I have a deep appreciation for laser safety haha

When I was ~12 years old one boy pinned me down and another one shone a laser pointer in my eye just for fun. Needless to say, this has been my „bad eye“ ever since (I’m 39 now)

Re: How I got my laser eye injury

#190

Post by hinkley »

rtkwe wrote: post #182
kqr wrote: post #179

Earlier quoted context omitted.

Wait, are barcode scanners lasers? I've always thought of them as red lamps because their cone spreads out so widely quickly.

It's a scanning dot moving fast enough to appear as a cone.

The stationary ones used to have a spinning mirror with a laser pointed at it. You used to be able to look in the machine and see it. Dunno how they do it now for the handheld scanners. Smaller mirror or some other trick like piezo?
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