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> On the plus side that makes diode lasers moderately safer for use by people that haven’t been specifically trained: you can see the beam and if you can then you at least have a chance to block it.

I disagree with this. Both diode and tube lasers can instantly blind you. But diode lasers can be a pain to block - because they’re in the visible spectrum you need specialized blocking materials that are opaque in that very specific part of the visible spectrum. Worse still, many have leakage into other frequencies, making them even more difficult to block. On the flip side, a co2 tube is much simpler - some common and readily available plastics transparent to visible light are opaque to the IR wavelengths emitted by co2 tubes, dramatically simplifying blocking material selection.

You should never operate any sort of cutting laser without an enclosure and safety goggles, and it’s MUCH easier to do this for co2 lasers.

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I second this; this is super bad advice. CO2 systems are comparatively safe from an eye damage perspective - unless you take a direct hit, (...don't, seriously, that's what interlocks are for...), 10.6um is strongly absorbed by your eye and you'll get superficial thermal damage, maybe cataracts or a corneal burn, but it won't get focused on to your retina so serious vision loss is unlikely. Polycarbonate safety glasses have a crazy high optical density at 10.6 and are suitable protective eyewear.

The situation for visible diode lasers is much worse. Sure, the power tends to be lower, but they're still powerful enough that looking at a diffuse reflection will result in dangerous power densities on your retina. Unfortunately, the brain is really good at hiding this sort of damage, so it's possible to not notice until it's too late.

1.064um fiber lasers are the worst of both worlds. Very high powers, invisible so you have no idea how much stray light is getting out or if you're staring at a reflection, and expensive + hard to verify safety glasses.

I like doing things with high power lasers (next up for the collection is probably a 355nm ns system?), but am glad that I had to take a lot of laser safety training before I bough my first big laser source.

Fun fact: in Uni people doing stuff with not so strong white laser are using VR headsets with see through mode

Sounds like quite a good solution actually, low latency and all. Do you know if they fitted any filter over the headset cams to protect those just in case?

Why would they need a filter? The laser light isn't making it directly to the eyeballs of the wearer.

The worst you'll get is 100% illumination on all pixels on the LCD inside the headset.

You can't stare at the Sun, but you can stare at a video of the Sun.

The question is clearly about protecting the camera from the laser.

Well white laser cannot be blocked with normal Kameras.

camera sensors are pretty easy to damage. a lot of people destroy their cameras by filming solar eclipses without taking any precaution

Yes, definitely. You will want to protect your camera sensor from a direct hit by a laser (or even an indirect one). Diffused is probably ok.

White laser? Rgb or something else

No, normal Laser which goes through a non linear optimal element. See supercontinuum

Ah yes, these are very good points. I will update the article accordingly, thank you.

Yes, you are 100% correct, my wording is sloppy and can cause danger to people operating this gear. If you can see the beam it probably is already too late! You should never get into a position where this is a possibility.

Edit: I've updated the article with a hopefully better text and a reference to your comment, if you could review it and indicate if I should make further modifications I'd be very grateful.

Please can you add a big bold warning right at the top of your article? As it is, the safety details are buried way too deep for casual readers who might be skim-reading by the time they get to it. Even a "heads up: this stuff can injure or blind you permanently if you don't follow safety procedures!" in the first paragraph would help.

Hey Charles, yes, I will do that. In fact as more and more feedback rolled in I realized that I should really lead the whole thing with a safety section, I will do some rewriting tonight.

A maker space I used to be a part of had a warning on our laser that said “DO NOT LOOK AT THE LASER BEAM WITH THE REMAINING EYE!” I feel like this should be the first sentence here.

It's in there already, even if not as the first sentence, but your plan is a good one.

Ok, the rewritten article is up, if you have any feedback I'd be most grateful.

The number of hobbyist diode laser machines that come with zero enclosure or air extraction is mind boggling. It then leads people to assume that stuff is optional. It’s not.

Yes, it is very much negligent on the part of the manufacturers, on the other hand, at that price point you should look at these as things that you can make a laser cutter from, not a complete product. For instance, my machine was after the initial build quite far out of square, it was a parallelogram rather than a square and it took quite a bit of fiddling to get it to cut square pieces. It also didn't want to stay level and that too took some work to correct.

These weren't small errors, > 2 mm in either axis across the 61 cm x 61 cm work area of the machine. But now that it has been set up properly it is quite usable.

A 'real' machine has a calibration procedure that will allow you to correct for such errors as well as a large variety of others but these cheap machines just output stepper pulses in fire-and-forget mode without any feedback at all besides the ability to re-home in case they get lost (and the homing switches are so crummy that I'm amazed they work at all). But that usually implies a ruined work piece.

Yep, IR lasers are much safer. You also have a bit of safety net because the eye won't try to automatically focus on a beam, resulting in a nice hole in your fovea.

That being said, it's also great to see the beam's location, so one possible solution is to mix in low-power red/green laser into your cutting beam. It can be as simple as gluing a strand from a fiber optic cable next to the main cutting head.

Careful with "IR" there. That's true for CO2 lasers, but ~1064nm is IR focuses fine but is quite invisible so it results in no blink or avert reflex.

From what little I know, I believe lasers up to 1mw are considered 'blink safe' in the sense that a quick enough blink response will save you from permanent damage.

Not relevant to laser cutting at those powers.

Be aware that the safe power limit strongly depends on wavelength.

Looks like the article has been edited to cross that bit out.

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