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What is more important?

clipk0

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What is more important you guys, mW or nm? Especially for melting/burning through things, which makes more of a difference. Thanks!:thanks:
 





Razako

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For burning you can't beat 445nm/450nm on a cost basis. 405nm is a little better at burning per mw, but 405nm units only go up to a watt or so. A 2-3W 445nm is probably the most cost efficient burner you'll be able to get.
 

Sta

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What is more important you guys, mW or nm? Especially for melting/burning through things, which makes more of a difference. Thanks!:thanks:

mW means the power of the laser. It's the raw number that says how many photons it's putting out. The wavelength (nm) doesn't really affect burning power that much, except that shorter wavelengths get absorbed by stuff a little bit better. Certain wavelengths like 405nm and 532nm can burn at longer distances, because the diodes/DPSS with which they are made have better divergence, than, say, 445nm. This doesn't have anything to do with the wavelength itself, though, rather with how it is made.

Here are a couple of videos by the great styropyro that should tell you a little about what different powers can do:

 
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diachi

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It's the raw number that says how many photons it's putting out.]

Just going to nitpick that a little bit and say not necessarily.

Power is simply a measure of energy per unit time. So 1W of laser light emitted for 1 second is equal to 1 joule of energy. P=ET, E=P/T.

The wavelength of a photon is proportional to the energy of the photon (And vice versa of course). Say you have a 1W 405nm laser and a 1W 650nm laser - they'll both produce 1 Joule of light energy over 1 second, however, seeing as your 405nm photons each have more energy than your 650nm photons there will be less photons emitted at 405nm in that 1 second interval to reach 1 Joule of energy output. So a 1W 405nm laser will be putting out less photons than a 1W 650nm (Shorter wavelength, higher energy) even though the output power is equal.

Hope that makes sense!

Your other points are spot on! :D

405nm also typically burns a little better (All things equal, such as optics, output power, beam shape etc) because shorter wavelengths can be focused to a smaller point than longer wavelengths. So you end up with higher power density and thus things burn better.

Which is somewhat related to what you were saying with 445nm not being quite as good as 405nm for a given power due to worse beam specs - worse beam specs often causing a larger spot and as such a lower power density. :D

Good touch adding those videos! :)

+5 ;)
 
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Just going to nitpick that a little bit and say not necessarily.

Power is simply a measure of energy per unit time. So 1W of laser light emitted for 1 second is equal to 1 joule of energy. P=ET, E=P/T.

The wavelength of a photon is proportional to the energy of the photon (And vice versa of course). Say you have a 1W 405nm laser and a 1W 650nm laser - they'll both produce 1 Joule of light energy over 1 second, however, seeing as your 405nm photons each have more energy than your 650nm photons there will be less photons emitted at 405nm in that 1 second interval to reach 1 Joule of energy output. So a 1W 405nm laser will be putting out less photons than a 1W 650nm (Shorter wavelength, higher energy) even though the output power is equal.

Hope that makes sense!

Your other points are spot on! :D

405nm also typically burns a little better (All things equal, such as optics, output power, beam shape etc) because shorter wavelengths can be focused to a smaller point than longer wavelengths. So you end up with higher power density and thus things burn better.

Which is somewhat related to what you were saying with 445nm not being quite as good as 405nm for a given power due to worse beam specs - worse beam specs often causing a larger spot and as such a lower power density. :D

Good touch adding those videos! :)

+5 ;)

I just learned something new :D
 
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Power is only half of it, divergence and getting that power where you want it is the other half, but the tightest focused 5mw red is still puny.

If you want to burn you cant beat the nubm44 or nubm06, if all you are going to use are off the shelf lenses then the 06 with it's tighter divergence is more fun.

Here is a nubm06 with it's factory Gball lens....now if you want to burn at 15 feet you will need to use some special optics, but divergence can trump power is many cases.


GET A NUBM06 HERE


THREE IMPORTANT WORDS - LASER SAFETY GLASSS Safety Goggles
 
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joeyss

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NM and then power.

~2mw of 612nm is still brighter than a 5mw red to me after my 612 hene warms up.
hell I only have 3 colors of green alone
520 532 and a 3mw cni 561 pen
 
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Hi,
Red has a good point here about divergence, the right lens makes all the difference by forming the beam to a finer dot signature. By doing this the energy density is concentrated into a smaller well formed area. Red is a divergence guy he will know more about a diode burning material

Rich:)
 
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What is more important you guys, mW or nm? Especially for melting/burning through things, which makes more of a difference. Thanks!:thanks:

Higher frequency can add to the ability to burn, but not nearly as much as the mw rating, of course divergence is also a factor, for instance most 405nm diodes are single mode and have better divergence that can offset higher power for say, popping balloons.

Here's an example of how a 1/2 watt single mode 405nm can out perform 2.5 watts or more of multi mode power.

2.5 watts of multi mode 445nm vs. 0.5 watts of single mode 405nm

The 445nm even need a helper lens to do the job....slowly.


2.5 watts 445nm multi mode.

0.5 watt of 405nm single mode.
 
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