Where did you get those facts? Do you mean that it is eye safe because the output is less than 5 mW when it reaches the eye? that number is only valid for IR filtered 532nm green lasers, a 5 mW 405 is a class 3 laser... You can't just assume that just because the output is lower than x mW it has to be safe... The rating heavily depends on the wavelength:
It depends on what you call "eye safe." If you aim a sketchy Chinese laser pointer directly into your unprotected eye, you're probably signing up for the white-cane brigade. I don't know anyone who would do that on purpose. So don't look directly into a 405-nm laser pointer, whether from China or otherwise. Based on actual measurements, I consider sunglasses to be adequate protection for short-term indirect viewing at 405 nm.
How do you know that?
There are millions of laser pointers out there, many of them with completely-bogus specifications. If indirect exposure were a widespread problem, we'd know by now.
I know a couple of guys with permanent eye damage from a laser, the damage also depends on the wavelength... It can either fry your lens or retina, the guys i know screwed around with 500 mW lasers and got a couple of dark spots in their vision. You only notice that sort of thing when you are staring at a white paper.
With a 405-nm pointer, the main hazard is not to the retina unless you look directly into the laser aperture, which we've already agreed to refrain from doing. The human eye doesn't focus well at that wavelength, and the lens is going to absorb a lot of the energy. As a result, longer-term exposure can be expected to cause cataracts. So don't do that, either. Dry your glue and move on.
And what IR line (your post has no pics)? A 405 nm diode laser shouldn't have a 808 nm line, those kind of diodes are only used in green laser pointers to excite the NdYAG crystal that emit at 1064.
There are thumbnails in my earlier post from yesterday showing the spectra of both the LED that comes with the adhesive kit and the laser. Are they not showing up?
I didn't know the IR line was there myself until your post prompted me to measure it, so thanks for that.
I was ass-u-ming that the pointers used fundamental-mode diodes made with GaN or some other wide-bandgap material. Wikipedia says that they can be built with GaAs IR diodes at 808 nm that are frequency-doubled to 404 nm, and that indeed appears to be how these pointers work.
Unfiltered 532-nm pointers are
considered especially hazardous because of their invisible IR emission. At 532 nm the beam is easy to see and avoid, but at 405 nm the apparent brightness is way down, making IR exposure more likely. It's a valid concern, given the combination of out-of-spec power output and inadequate or nonexistent IR filtering, and one I wasn't aware of.
Anyway, Cerberus is right, this is both off-topic for the thread and interesting enough for its own thread. I won't post any further to this one, but if it's possible for a mod to move the messages to their own thread, that would be great.
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