I was in a discussion last night with some folks on FB that were absolutely convinced that their generic 60 watt C02 lasers were capable of producing 1000 dpi engravings. Based on what I know (or at least what I think I know) about the laser physics and high voltage power supplies I told them that 1000 dpi was not possible. Most of the power supplies in this market have a response time of 1 millisecond (or greater) so if the laser head is moving at 100mm/sec it will cover about 4 inches in 1 second.
So it seems to be at the modest scan speed of 100mm/sec 250 to 300 dpi is about the best resolution you can hope for.
If the speed is slowed down any more the power level of the laser would need to be lower as well and what I have been taught about CO2 glass tube lasers tells me that you need to have at least 7% power to have a stable beam formed. So there is a real lower limit on the power level. I did not even get into the actual size of the dot being produced, that is whole nother can of worms.
The people I was chatting with were not impressed with my logic, they felt they were able to do 1000 dpi all day long and I was a heretic and a scoundrel for questioning them.
Am I wrong? If so what did I miss? Does some manufacturer of cheap generic power supplies make a super fast unit? Are there some special glass tube lasers that can run at really low power levels (one guy told me he routinely used less than 1 percent power).
I am sure someone in this group knows the answers.