Maybe not pointless - but the dangers of IR are GREATLY over-rated. No joke ! With as difficult as IR is to collimate, it fans out, and disburses at a HUGE rate - the IR that the average (or not so average) pointer from like say, Ebay or whatever - that IR is not focused, it leaks out of the pointer, and fans out to the point where it is no longer even in the beam after about 12" or so....maybe a TINY bit still in the beam, but so diffuse that it doesnt matter. The MAIN objection to greenies from ebay and such that have a ton of IR is that you are not paying for green - you are paying for a mixture of green and IR - and that is a rip off. I know I could argue with most anyone on here for hours, days, weeks, years, whatever - but...sometimes I am 100% right, and I will dig in like a dog with a yummy bone, and fight about it In THIS case - I am most certainly correct - as I have experimented with IR diodes, arrays, and semi-collimated laser pointers. And my conclusion is irrefutable. Sorry to bring this maybe a little off topic, as it was not really about the dangers - I believe the demo was jjust showing all the IR that CAN possibly pop outta a greenie if it is not built properly....
I agree that the dangers of unfiltered lasers are way out of proportion. People almost seem to think that a 100mW green laser is 100% eye safe whereas a 100mW green with 10mW IR will take out your vision.
However, maybe its best to leave that misconception stand? It stops some people from falling for those scams at the very least. And there are some valid issues I guess. First off, normal green-filtering goggles do not filter IR, so that can provide a false sense of security. Also, depending on where your eyes are focusing, even though the IR is diverging, your eyes can focus it to a nice tight spot on your retina. So I guess there are SOME issues with IR.
But yeah, the idea that green is fine and IR is the dangerous one is completely backwards.
ok maybe I misunderstood, but form what I gather, he's only filtering the output from the raw IR diode, there's no longer a green output, only IR so if you filter off the IR, you get... wait for it.. nothing.
which is duh.. obvious. I know every dpss laser has some residual IR. but videos like this ( at least what I think it is because the video of the "IR" looks exactly like a unfocused bare diode output ) are just decpetive.
well if the IR was focused it could be a problem, but since the optics are usually for the another visible color it's always going to make the IR output pretty far off, both 808 and 1064. there will be a cone of IR and a beam of visible laser light. The ir in the cone might be 10-15 mw, but it's not focused and it's diverging quickly, so beyond a couple of inches past the aperture and it's almost pointless. IF you managed to get a meaningful amount of the IR you'd have to be into the visible output of the dpss laser.
the only real way to get hurt IMHO fom a dpss laser from the IR leakage is if the pointer broke somehow right at the ktp crystal so only 1064 was coming out and some idiot decided to take a look in the end when it was on. the 1064 output would be invisible and there'd be a faint redish glow from the residual 808.