[Konstantin]

Hello.
I am trying to google out the specs for the chinese laser tubes but it isn't yielding any results that include beam divergence specification.

If you have a datasheet or know the divergence of your laser please post it.

From what I understand if the beam diameter at the OC is 4mm and the beam diameter 1m from that spot is 11mm then beam divergence will be 11-4 = 7 mRad.

[yamingf]

usually divergence of the CO2 laser tube(60-120W) is around 2.2mrad, the beam divergence of a laser beam is a measure for how fast the beam expands far from the beam waist. from laser tube specifically designed for laser engraving/cutting point of view, its not as important as beam diameter or sopt size, after all, spot size is the key parameter we want as smallest as possible, but it can not be smaller than wavelngth of your CO2 laser usually around 10 mcron(0.01mm), in reality, that will be good enough if you can get spot size around 0.3mm-0.5mm.

[Konstantin]

I guess I didn't explain myself properly.
I am in the process of building my XY table for a laser cut/engraver.
Originally my plan was to make a table to be able to accept standard size mdf sheet (since I ve got a nice deal on some T slotted aluminum). With flying optics setup the beam would have to travel about 4 meters to the farthest end of the table.

Then I learn about beam divergence. For example Coherent Diamond G100 has a divergence of 11mRad with beam diameter at OC being 2.3mm, that makes it into 11x4 + 2.3 = 46.3mm beam diameter.

Do you think beam divergence is important now?

Synrad 48 series has beam divergence of 4mRad and that is much better than Coherent's.

2.2mRad would be AWESOME, I mean it. AWESOME. But I don't think that it is so low.

So without some optic compensation a simple flying optic setup will be limited in XY table size because the focal point will shift as beam diverges.


With this in mind I will have to be a bit more modest in my XY table size until I can come up with some solution to this.

I am citing Coherent and Synrad because their datasheets are available, my modest budget does not allow for such great laser heads.