Potential list of Laser wavelengths for ablation of materials (burning)

Wanting to make a CNC Laser, I needed to know what the ablation wavelength of Copper (Cu) is, now sure I asked and was pointed towards a CO2 laser which has a wavelength of 10.5um granted just about EVERYTHING absorbs that, but until I actually got one and in the price/size/power range I wanted, I wanted to see what other wavelengths could be used for other ablation purposes, so I set out to start finding that info.

Low and behold I found:
NIST: Basic Atomic Spectroscopic Data - Perodic Table

which has a periodic table that you click and it takes you the basic data, but for our purposes if you click on strong lines (right next to to atomic data) it lists the ablation (absorption) wavelength of the material, so for the example of Cu it starts to oblate at 2000nm in air.

Wanted to at least attempt to contribute to the community rather then just take from it, so enjoy, I'm still trying to locate a list of more common things or of compounds like plastics or plastics of a certain color, or other common materials.

Nice find. However emission data and absorption data are two entirely different things. Those tables deal with spectral emissions.

I'm not sure where you saw they were absorption data. It says fairly clearly in the 'introduction' that it's emission data.

I'm still not sure why your dead set on trying to use a laser for PCB etching. photoresist transfer and chemical etching will be both a heck of a lot cheaper, as well as faster.

I've seen it done with CNC before but it was still not using a laser. It was done using a dremel or some other small high speed rotary tool.

... agreed ... kind of ... that is, I understand the OP's intent, and I (mainly) understand his reasoning/interpretation, BUT IF;

... you click on Carbon, the interpretation falls apart(?)
... unless I am missing something.

Hint for copper...UV and CO2

To you get an idea you can read this

http://www.laservia.com/PDF/Nepcon99.PDF

And this.

http://www.circuitree.com/Articles/Feature_Article/e13efe7a6afe7010VgnVCM100000f932a8c0____

And you can look at this machine


LPKF ProtoLaser S

:cryyy: :sigh: I had a feeling i'd screw this up, I was basing it on what was discussed in my other thread where a CO2 laser emits 10.5um IR, and when I looked at the hard lines for copper (since I'm dead set on doing this), the list for in air wavelengths fell into the IR spectrum and included the 10.5um.

So thats how i came to the conclusion of the lists wavelengths being absorbtion wavelengths, and the fact that if you were to burn copper it burns green, guess I'll go back to trying to find an actual list of different materials ablation wavelengths.

From the links piferal posted, you need UV to remove the copper. Which probably means a tripled ND:YAG.

(Kmor) - I tried to do a google search - got MANY hits, mostly "dead-ends"; got a little too overwhelming.

Maybe NO-ONE has done an exhaustive study... but it is a worthwhile pursuit. I will try again myself later.

I believe emission lines and absorption lines of a material are usually very similar, if not identical. The change in the electrons' states emit or absorb photons. These changes in energy levels are quantized, and should be the same for jumping to a higher energy level (absorbing) or jumping to a lower energy level (emitting). I am not absolutely sure of this.