Lasers are used for many different applications and come in a large variety of powers and parameters, so it wouldn’t be fair (or logical) to require the same sort of safety measures for industrial laser welders as laser pointers or barcode scanners.
There are many specifications used to define optical components, such as lenses, mirrors,
windows, etc. Some, like focal length, might seem obvious. Others, like power
and centration, might not be as self-explanatory.
Here is an incomplete glossary of some of the most commonly used specifications for