1467. I work in a company shop that uses a 600-watt laser with a wavelength of 1064 nm. How safe is this machine? What is the radiation hazard, if any? I've noticed that my eyes feel strange after working with it for 4-5 hours. It also has an uncomfortable smell. — EC
The laser you're using is a neodymium-YAG laser. It uses a crystal of YAG (yttrium aluminum garnet), a synthetic gem that was once sold as an imitation diamond, that has been treated with neodymium atoms to give it a purple color. When placed in a laser cavity and exposed to intense visible light, this crystal gives off the infrared light you describe. You can't see this light but, at up to 600 watts, it is actually incredibly bright. You don't want to look at it or even at its reflection from a surface that you're machining. That's because the lens of your eye focuses it onto your retina and even though your retina won't see any light, it will experience the heat. It's possible to injure your eyes by looking at this light, particularly if you catch a direct reflection of the laser beam in your eye.
In all likelihood, the manufacturer of this unit has shielded all the light so that none of it reaches your eyes. If that's not the case, you should wear laser safety glasses that block 1064 nm light. But it's also possible that the irritation you're experiencing is coming from the burned material that you are machining. Better ventilation should help. High voltage power supplies, which may be present in the laser, could also produce ozone. Ozone has a spicy fresh smell, like the smell after a lightning storm, and it is quite irritating to eyes and nose.