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FrozenGate by Avery

Questions about CNI UV.

There are UV laser diodes, absolutely. UV can be more dangerous than IR, but in different ways. It's still dangerous to your retinas etc, but shorter wavelength light such as blue, violet and UV is more energetic, meaning each photon carries more energy than if the light were longer wavelength. If you were to take a 1W red laser and a 1W blue laser and compare them you'd find that at 1W the blue laser is emitting fewer photons than the red laser, but the photons are more energetic.

Short wavelength light is less discriminating about what it destroys through heating. With red lasers, dark substances burn much more easily than light colored substances. The same is true with violet, but violet will ALSO burn many lighter colored objects that the same amount of power in red would not.

As you get into even shorter wavelengths deeper in the UV range, thought to begin below 325nm or so, there is a skin cancer risk with direct exposure.
 
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so the deeper the less reflectable? and also less visible i guess. But I heard that there are far stronger IR diodes available than UV so it probably depends on the material right? for engraving in metal uv would be better?
And I heard IR is good for engraving glass (how comes it doesnt melt the glass lense then?)
 
The change in burning effects of various wavelengths can't really be characterized as being linear across the spectrum. Some substances absorb more IR than UV and vice versa, resulting in effects that are "out of character" so to speak.. What I said before was only a general guide. As an example, many things that are opaque to our eyes are transparent to certain IR wavelengths.
 
hmm ok cool
and about the glass? i know there are lasers that engrave glass. do they still use glass lenses?
 
CO2 lasers are used for engraving glass, and they are IR, but they are very far into IR at 10,600nm. At that wavelength glass absorbs most of the energy and coverts it to heat. CO2 lasers do not use glass lenses, they use ZnSe.
 
so UV diodes are less "picky" about heating up materials but IR lasers are available in higher powers right?
So what are IR and UV diodes used normally for?
 
UV lasers are used for fluorescence experiments throughout the scientific world, biology, chemistry, physics, etc. Not a lot of hobbyist uses other than novelty or personal small-scale experimentation.

IR laser diodes are most commonly used for DPSS pumping and in CD players.
 
and wich lasers are used for cutting metal? isnt it hard to find one that isnt reflected by its shiny surface?
 
Metal's another good one for CO2 lasers, but it can be done with extremely high-powered industrial solid-state lasers as well.
 
Power is the most important factor when cutting, etching or burning anything. More power = more heat transferred. Wavelength is a secondary factor, but having tons of power is most important.
 
Power can overwhelm reflective materials. Some of the light will be reflected, but some will be absorbed. If your power levels are high enough, the absorbed portion will still be strong enough to burn.
 
When cutting metals, the metal's conductive heat index and melting temperature will also be an important factor. For example, a higher melting less conductive metal may require more laser power than a lower melting more conductive metal like aluminum or copper because the AL/Cu can wick heat away faster.

It's really all about energy density and thermal properties (conductivity and melting) when cutting materials.
 
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