laser for cutting dollar tree foam board

[swamidog]

you might have better luck if you fiber coupled and collimated it. the higher power 808 diodes tend to have poor beam specs.

be aware that 808nm is considerably more dangerous to your eyes than 10,600. Enclose everything and make sure you have proper goggles.

Chris I know you are very knowledgeable about these laser cutters. I'm trying to think outside the box a little. What if he took a 808nm pump diode. I know its not as high a wavelength as the CO2, but may give the results he is looking for far cheaper than a CO2.
I've thought about doing this my self.

[VDX]

... I'm using fibercoupled IR-diodes (mostly 975nm, but have some 808nm too), but their results are even more dependant on the materials coulour, than with the 445nm.

My estimations (gut-feeling) for min. powers to cut this sorts of white foam are around:
best spot diameter / min. power / @wavelength
0.04mm / >300mW / @405nm
0.05mm / >1.5W / @445nm
0.12mm / >15W / @808nm = fibercoupled, 105µm fiber
0.15mm / >25W / @975nm = fibercoupled, 105µm fiber
0.1mm / >1W / @10600nm = cheap Chinese CO2-laser-tube with 40Watts
0.05mm / >500mW / @10600nm = sealed RF CO2-lasers from Synrad

Viktor