One CO2 glass tube laser tube manufacturer specified that the laser tubes were measured at a distance of 700mm.
Why not at any practical distance, for example, 100mm or 1000mm? The divergence ought to be small for such close distances.
Am I overlooking something?
I am building a laser and I am reserving space for the power meter between the tube output and the first mirror so the distance will only be around 50mm.
