I have a 300w co2 rf laser and i want to make diy copper mirrors.
40mm diammeter 4mm thick is ok ?
How to polish flat the copper?
I have these lapping papers https://www.aliexpress.com/item/4000496030315.html
If i make flat the copper in a surface grinder machine then polishing/lapping by hand should work ?
Also how to polishing/lapping the optic fiber of a diode laser 940nm ~100w ?