I have no idea, but the microscope he's looking through could certainly have UV protection built-in. Or perhaps the pulses are so short and small that the cumulative risk is negligible?
Either way, it seems to me like there could be ways for it to be safe enough to require minimal PPE while still producing some non-zero amount of UV.
I'm also thinking about skin exposure. Fortunately glass optics are at least opaque to the most dangerous bands of UV, but not to retinal blue, which has its own special place in the regulations.
I have no idea, but the microscope he's looking through could certainly have UV protection built-in. Or perhaps the pulses are so short and small that the cumulative risk is negligible?
Either way, it seems to me like there could be ways for it to be safe enough to require minimal PPE while still producing some non-zero amount of UV.