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FrozenGate by Avery

Help choosing 445nm goggles






Ash said:
532nm causes fluorescence? On what material? :scowl:
I must be using the wrong green laser. :banghead:
Click to expand...

Try shining it on some orange/red plastics, you'll see a very strange yellow dot fluoresce on certain materials around that color range.
 
Laserglow's goggles are not misrepresented.

If your 447 nm laser is, let's say, 500 mW, then the goggles with OD 7 will transmit only 0.00005 mW (50nW). However, if you point the laser at just about any surface, the short wavelength will induce a ton of fluorescence which will be at longer wavelengths. I'm willing to bet that the spot that you're seeing actually appears bright orange or yellow, right? These goggles cut off just over 532 nm, so they will transmit a great deal of the emitted light which is a product of the fluorescence. This is why you can "see" your 447 nm laser through the goggles.

If you want to check this yourself just shine the laser directly at the goggles (not while they're on your face, of course) and see how much laser light comes through the other side. Don't do this for too long, though, since the goggles are only designed to take a direct hit for a limited time. I guarantee you the OD 7 goggles are not transmitting more than 10^-7 of the initial power.
 
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I have a spectrophotometer, and at full power a whopping 3uW of 633nm is nicely visible on a ~1x1cm surface in a somewhat badly lit room. Below 0.5uW you lose the spot. With only two monitors as a light source 20nW is still nicely visible, without them around 5nW. That's no much.
 
Justin said:
Laserglow's goggles are not misrepresented.

If your 447 nm laser is, let's say, 500 mW, then the goggles with OD 7 will transmit only 0.00005 mW (50nW). However, if you point the laser at just about any surface, the short wavelength will induce a ton of fluorescence which will be at longer wavelengths. I'm willing to bet that the spot that you're seeing actually appears bright orange or yellow, right? These goggles cut off just over 532 nm, so they will transmit a great deal of the emitted light which is a product of the fluorescence. This is why you can "see" your 447 nm laser through the goggles.

If you want to check this yourself just shine the laser directly at the goggles (not while they're on your face, of course) and see how much laser light comes through the other side. Don't do this for too long, though, since the goggles are only designed to take a direct hit for a limited time. I guarantee you the OD 7 goggles are not transmitting more than 10^-7 of the initial power.
Click to expand...

See here for wicked's goggles, they are very misrepresented:
Yfrog Video : yfrog.com/msoemvswickedlaserz - Uploaded by Imageshack user

:barf:
 
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I ran a calculation the other night I was going to post but I lost the post accidentally clicking on a link. In any event, a person can see about 100 photons and be able to identify it. It is possible to even see one but most people don't recognize it. I figured a one watt 445nm would give you a little over two billion opportunities to see one hundred photons per frame if your vision was processing at 100 frames per second with OD7 glasses on. Although you don't really process vision in this manner, it is a good analogy for the underlying neural processes. Basically, if you took a direct shot to the eye through the filters you would see some 445nm photons.

Justin is absolutely accurate in his statement regarding fluorescence and their filters are OD7. I was pounding away with a 1.1mJ 532nm q-switched laser running at 10kHz the other day and I could barely see anything (diffuse reflection) through my OD7 filters. For those not familiar with pulsed lasers, each pulse is equivalent to 11kW.
 
Justin said:
Laserglow's goggles are not misrepresented.

If your 447 nm laser is, let's say, 500 mW, then the goggles with OD 7 will transmit only 0.00005 mW (50nW). However, if you point the laser at just about any surface, the short wavelength will induce a ton of fluorescence which will be at longer wavelengths. I'm willing to bet that the spot that you're seeing actually appears bright orange or yellow, right? These goggles cut off just over 532 nm, so they will transmit a great deal of the emitted light which is a product of the fluorescence. This is why you can "see" your 447 nm laser through the goggles.

If you want to check this yourself just shine the laser directly at the goggles (not while they're on your face, of course) and see how much laser light comes through the other side. Don't do this for too long, though, since the goggles are only designed to take a direct hit for a limited time. I guarantee you the OD 7 goggles are not transmitting more than 10^-7 of the initial power.
Click to expand...

Thanks Justin. I did actually burn my goggles a little bit with my 1W 445, but I can confirm I just seem to get a relatively dim orange glow on the other side of the goggles while pointing it straight at them.
 
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