This... has got to be the stupidest thing I've seen online in quite some time. At the very least, something like that should come with a free pair of goggles. And of course they basically look like lightsabers / toys.
There are legitimate uses for these, and for a second I wanted to give them the benefit of the doubt- and then I read their descriptions.
> The 50000mW 532nm Green Beam Light Separate Crystal Attacking Head Laser Pointer Pen is a versatile tool designed with a variety of functions. With 50000mW high power, it produces a super bright green beam light full of energy that can be used to light a cigarette, cut the paper even plastic into pieces, shoot the bird, and more. Moreover, advanced separate crystal design makes it more stable and durable during long hours of continuous running. And its attacking head is ultra solid even in the harshest environment. Don't hesitate to get one now!
They're taking a tool and turning it into a ridiculous toy. I can already see someone trying to "light a cigarette" they're holding in their mouth and blinding themselves in the process.
That being said a lot of them do come with goggles.
> And of course they basically look like lightsabers / toys.
If I'm remembering correctly, a few of the more idiotic 'laser pointer'/'geneva convention violating blinding device' retailers got sued by Lucasfilms for intentionally looking like lightsabers - so you're not wrong!
> I would not trust a pair of free goggles to protect my eyes from a 50 W laser.
FTFY: I would not trust a 50 W laser.
I wouldn't trust it not to blind me, not to blind someone else, not to make burn marks on my walls, not to catch fire randomly, and not to actually output 50W.
This article [0] is a 'fun' look at the laser regulatory environment. Unfortunately, that environment doesn't seem to have teeth yet.
I was once helping troubleshoot a UV laser in a lab. It was an IR Nd:YAG pulsed laser with two frequency doublers, and I think the rated output was something like 1 J. The measured UV output was essentially nil. We took off the second doubler and fired the laser at the side of a desktop computer we didn’t care about while wearing serious goggles. There was a little snap and the paint got replaced with a shiny metal spot. :) You do not want a laser like that anywhere near your eyes.
The point of the goggles isn't to protect you from a 50W laser. Or even 1W laser (most googles will quickly melt).
The danger is reflections, at over a watt even the dot that the pointer produces on the wall can be bright enough to cause permanent blindness unless with goggles.
Those free pair of goggles are the biggest lie of the whole package. They cost ~$1 and are often not able to protect your eye. Youtuber styropyro did a roundup on this(sorry for no link)
While I don't believe the 50W of these, green is the most dangerous, as it almost always has some IR noise in it, and your goggles, even if best most likely can't protect from green and IR at the same time.
I mean, there’s no way they’re 50w. The best diode lasers for cutting are about 7W. I have a 4.2w laser on my CNC machine for engraving. That’s very powerful, but, nowhere near 50W. For reference, a 50W CO2 laser is typically used in a professional quality machine for cutting/marking/engraving.
Good smell test for those claims: what battery can you hold in your hand that can output 50W?
> what battery can you hold in your hand that can output 50W?
Batteries used for drone racing can easily be held in your hand and can put out hundreds of watts.
Most flashlight and laser pointers use 18650 batteries. Something like the Samsung INR18650-20S can put out ~100W from a slightly bigger form factor than AA batteries.
> what battery can you hold in your hand that can output 50W?
Laptop batteries all day, so to speak...more typically for about an hour of runtime at that power consumption level between recharge. Not quite following your analogy.
Sigh. There's no way they're getting a 50w out of a single diode. 50w is what our co2 laser is at our hackerspace, and requires a 1.5' tube, specialized PSU and watercooling.
These pictures look like the 2w and 2.5w variants on Aliexpress.
Yeah, sites like that are pretty much in the sweet spot of uselessness - lasers too powerful to use as laser pointers, too low quality optics to use for engraving or other laser CNC projects, too cheap to actually deliver the rated power, and too outside the law to give a fuck about false advertising.
There are less-sketchy looking offerings in the 7W range for a similar form factor, though - see [0]. Of course, I'm still not sure if there's such a thing as a 'reputable' site in that segment...
Are you planning on going outside with it? If so, the answer is "Probably less than 5mW" - the legal limit for a Class 3R laser. Anything higher presents a risk of blinding.
So, 10,000x less power than the lasers on that webpage above.
Those seem to show up in the 500mW+ range, with 2000mW being enough for most softwoods (among other things). Industrial applications seem to range from 50 to 5000+ watts, but the lasers used there are likely to be better focused than the laser pointers you'd find off a site like the above.
And if you buy a laser CNC machine, it'll typically have interlocks present to keep you from accidentally blinding yourself. (which is a real possibility - if the material you're cutting has shiny inclusions, the wrong reflection can blind you)
"The wrong reflection" doesn't give the right impression. The point a 100W laser projects against e.g. a wall, when viewed at 1m distance, can damage your eye. Even if perfectly diffuse. Even if invisible.
I recommend taking a laser safety training class. At least the ones focusing mostly on show lasers are widely available to the general public, and not expensive. It'll cover the optical dangers at least. Possibly it'll also build some respect for lasers, and maybe make certain things legal for you (important esp. after something goes wrong).
For machining lasers, there's a bunch of extra dangers to you _and_ the machine (e.g. particle exhaust, fumes, certain materials, fire risk (and secondary risk when putting it out!), very high voltages, human errors (I'm serious! and incl. both you and other/untrained people), legal requirements, overheating, electronical failures of the controller or interlock or (very relevant for hobbyists) plain bugs).
On the upside, hobby CNC lasers are often in the order of 100W (appropriate for cutting plastic/wood, engraving glass, and marking metal (with marking spray)), and CO2-based (10μm). A small stone brick will easily work as a beamdump. Basically _any_ thin plastic sheet will easily block secondary beams at this wavelength (so counter-intuitively the laser being invisible is an advantage!). And if the laser is dispersed enough possibly even direct hits, for a very short amount of time (up to seconds). (This is no excuse to save on the goggles.)
Do not trust cheap "complete, in a safe box" CNC lasers bought on the internet. They work, but require _extensive_ rebuilding to be safe.
It's possible and fun to work with lasers as a hobby. But please stay safe! If you can, don't go alone, find a fablab or hackerspace, maybe even build it there.
How thin of softwoods are you cutting? Event consumer-grade products like Glowforge are 40W, so I have a hard time believing a 5W laser is practical for much. (FWIW I maintained a 65W CO2 laser cutter for a while.)
People haven't quite grasped the stupidity/danger of laser pointers yet, I'm afraid. Check out this page with a variety of '50W' lasers: https://www.laserpointerpro.com/attribute/power_50000mw-lase...