dreaming of an ultraviolet handheld pointer

[cev1]

Virtually everything you "see" below 400 nm is fluorescence. Your retina and vitreous humour fluoresce at these wavelengths, so you can't even make an honest judgement whether you are "seeing" 400nm or something redder. This effect is especially pronounced if you have a very tiny source, like the output of an optical fiber. You will see a glow around the tip of the fiber coming from bulk fluorescence in your eye.

Cyparagon: All THG crystals will have SHG also. So, for instance, a tripled YAG will have a lot of 532 coming out (and some 266nm also). These systems require harmonic separators to pick the output.

ARG: temperature tuning in 405nm diodes is really bad, about 1nm per 20C. There are plenty of technical issues that crop up once you go below 10C or so (condensation is the first).

I think the only market that uses 375 is the science market, and it is, unfortunately, never going to blow up.

 

[Sigurthr]

Intraocular fluorescence is indeed an issue, but it typically presents as longer wavelengths, so unless it washes out the shorter wavelengths completely, you would still be able to see the UV.

 

[HitShane]

They are used for looking at DNA and particle trapping...

 

[cev1]

We have 375nm LD's. The longer-wavelength fluorescence generally overwhelms the fundamental in a typical viewing scenario. We generally view this as a good thing since we can easily see the beam.

 

[Cyparagon]

They are used for looking at DNA and particle trapping

Source?

 

[HitShane]

Source?

Optical trapping and manipulation of neutral particles using?lasers

Comparative analysis of different laser systems to study cellular responses to DNA damage in mammalian cells

 

[Cyparagon]

That's not looking at DNA, that's destroying DNA.

 

[lazerphase]

I believe you need to go as low as x-ray and gamma rays to actually destroy DNA... just saying, I may be wrong but im pretty sure.

 

[Cyparagon]

^Why do you think tanning and sunburns lead to cancer? Tanning beds do not contain cobalt-60 last time I checked.

 

[Sigurthr]

^Why do you think tanning and sunburns lead to cancer? Tanning beds do not contain cobalt-60 last time I checked.

Hehe, give the new age folks a chance and I'm sure they'll market a "healing energy cobalt ray" tanning bed.

Cyparagon is right though, UV thoroughly destroys DNA, denatures proteins, and all around ionizes atoms.