Yeah, figured that. Would be surprised if it was part of the original design. Not something any commercial laser has at our work. But at work access control is done manually for the Class IV spaces. Thinking it was added about the same time as the pass thru shields. Very late and in response to external forces.
Yes I think you are right there. I have locks on my lab and my workshop so I can stop my wife walking in when I am doing class 4 experiments with lasers. Far more dangerous than a GF.
Class 4 lasers are required to offer it. It’s a strange requirement, though, because use of it is not required by any standard or practice. Go figure.
It was included in the original design (and included in our first CDRH regulatory filings), but the implementation was never particularly visually elegant so I see why you might think otherwise.