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Laser Products I Hate

funraniumlabs.com

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Re: Laser Products I Hate

#51

Post by avian »

wnkrshm wrote: post #47

I work with lasers and we get a yearly security training on staying safe with lasers (the whole shebang, videos of cow-eyes exploding from diffuse scattering of a cutting laser, cutting pizza, photos of scars of accidents, post-trauma photos of retinas etc). It is indeed terrifying to see how easily you can get tools that can cripple people without people being aware of the danger.

I've spent some time in a lab with an optical table and what was probably a 10 mW helium-neon laser. Doors locked when the laser was on, warning signs, protective eyewear and strict procedures during experiments. And then you go out and see drunk people at parties with lasers from eBay of unknown power pointing them at random people. The lab experience made me really paranoid about anything that involves lasers and I completely understand the author of this article.

Re: Laser Products I Hate

#52

Post by nkrisc »

microcolonel wrote: post #24
atemerev wrote: post #8

I don't know, looks like an advertisement to me. Fun, dangerous, barely legal -- what's not to like?

Yeah, I don't really see the issue. People play with knives, operate firearms, use table saws, and cross the street in traffic all the time. The stakes are high in life, and if you're not careful you might poke an eye out with that thing, but what fun is a world where everything is engineered to be too dull to poke an eye out?

Drop your butterfly knife, you might just hurt yourself. Knock over that Cubiio, you might blind your neighbor in the building next to yours.

Re: Laser Products I Hate

#53

Post by gambiting »

wnkrshm wrote: post #48
jdietrich wrote: post #34

Earlier quoted context omitted.

It's not difficult to track eyes consistently using computer vision. It's not difficult to aim a laser beam using a mirror galvanometer. If you're struck in the eye with a UV laser beam, the blink reflex doesn't kick in - by the time you've noticed the pain in your eyes, it's already too late. The beam doesn't have to track with particularly high accuracy to cause certain blindness, especially if there's an array of…

A UV-laser would be humane, since UV (and shorter wavelengths) will interact with the outermost portion of your eye - visible light or the near IR (up to 1500) is what your imaging system operates on and it's focused onto the retina. Edit: Also, the blink reflex isn't fast enough to save you from damage if the Class is higher than Class 2 (and even then it's a roll of the dice, since there are some who don't have tha…

Can you expand on why that would be humane?

Re: Laser Products I Hate

#54

Post by Filligree »

gambiting wrote: post #53
wnkrshm wrote: post #48

Earlier quoted context omitted.

A UV-laser would be humane, since UV (and shorter wavelengths) will interact with the outermost portion of your eye - visible light or the near IR (up to 1500) is what your imaging system operates on and it's focused onto the retina. Edit: Also, the blink reflex isn't fast enough to save you from damage if the Class is higher than Class 2 (and even then it's a roll of the dice, since there are some who don't have tha…

Can you expand on why that would be humane?

At a guess, it might be possible to at least partially fix the damage afterwards, by scraping off the damaged cells.

I wouldn't call that "humane", and it is a guess; it might not work at all. Nothing to do with war is 'humane', though.

Re: Laser Products I Hate

#55

Post by MarkMMullin »

Hmmm - one serious thought - 'makers' thinking of playing with 1+ watts should also seek out videos of what happens to normal consumer and better non laser grade optics when used as focusing or steering elements - I knew of a lab that basically had very fine powered optical glass blown into the nearby walls (it was empty during the test) - and one less serious thought, from the same lab where I first encountered this sign... "Do not look in the laser with your good eye" :-)

Re: Laser Products I Hate

#56

Post by pjc50 »

fest wrote: post #42
analog31 wrote: post #15

Earlier quoted context omitted.

I have Hobbs, and it's a great general book. But it may fall into that fine literary genre of "explanations for people who already understand things." Hobbs assumes a fairly advanced understanding of physics and electronics. You might be able to learn how to make gadgets that work at the prototype level, but designing a potentially dangerous product is engineering. I don't know how you do that without working as an e…

On a related note- do you know of any books that cover diode laser safety? Specifically, I'm working on a FMCW laser rangefinder (hobby project to teach myself more of analog electronics) and would like to know what is the maximum optical power I should use.

There's actually a good quick guide to this in the article: stick to the laser pointer classification of less than 5mw.

Re: Laser Products I Hate

#57

Post by pjc50 »

stavros wrote: post #19
gambiting wrote: post #16

Earlier quoted context omitted.

If I absolutely had to pick, and the choice was between 1) get shot and maybe survive; or 2) 100% chance of getting blinded - I'd pick the first one.

Why are you comparing a weapon that has to hit a whole person and misses to a weapon that has to hit a 5mm retina and somehow never misses?

A sufficiently powerful laser - over 0.5W - can cause blindness from diffuse reflection. A 100W laser fired into a room with white walls for a fraction of a second can permanently blind everyone whose eyes were open at the time.

Re: Laser Products I Hate

#58

Post by fest »

pjc50 wrote: post #56
fest wrote: post #42

Earlier quoted context omitted.

On a related note- do you know of any books that cover diode laser safety? Specifically, I'm working on a FMCW laser rangefinder (hobby project to teach myself more of analog electronics) and would like to know what is the maximum optical power I should use.

There's actually a good quick guide to this in the article: stick to the laser pointer classification of less than 5mw.

I'm more interested in things like: if the diode is on for half the time (50% duty cycle), can I use 10mW? if I transmit a high frequency chirp with even less total duty cycle, can I use even more power?

Not that it really matters in my case: I will probably scrap the project when/if I make a good enough amplifier stage and phase detector for short range where 5mW should be enough.

Re: Laser Products I Hate

#59

Post by analog31 »

fest wrote: post #58
pjc50 wrote: post #56

Earlier quoted context omitted.

There's actually a good quick guide to this in the article: stick to the laser pointer classification of less than 5mw.

I'm more interested in things like: if the diode is on for half the time (50% duty cycle), can I use 10mW? if I transmit a high frequency chirp with even less total duty cycle, can I use even more power? Not that it really matters in my case: I will probably scrap the project when/if I make a good enough amplifier stage and phase detector for short range where 5mW should be enough.

Well, Hobbs is also the place to go for how to make that amplifier stage. He has some articles online for photodiode front ends, that are quite informative.

Admittedly I've never looked into those issues because the gadgets that I've helped design are all Class 1 -- the system is fully enclosed and interlocked.

Re: Laser Products I Hate

#60

Post by agumonkey »

anfractuosity wrote: post #6
damnfine wrote: post #2

Interesting that he compares them to firearms, and all that entails. With power levels increasing, we may see a viable laser rifle soon, and with it, a need for a new regulatory structure (or adoption and expansion of an existing one, atf, etc.) They seem to have many of the same public safety aspects, but will someone popularize a legitimate 'Sporting Use' for these devices before they are sold as 'Death Rays to Bli…

I wonder how practical a portable laser gun would be, as I'm imagining a laser diode array would need to be amazingly powerful (I'm assuming much greater than the 40W version in the video?) and they'd require a very beefy power source. It seems diode lasers are up to 60% efficient? It looks like you can get extremely high power pulsed laser arrays though.

I also wonder how quickly damage occurs when using all 8 beams through to focusing lens.
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