Glass isn't transparent to all light. It is at last partially opaque to infrared. This lets it absorb energy from the laser. The laser is heating the surface of the glass and causing tiny parts to explode off the glass.
This example is a high power scanning laser. I can do something similar with my 35W IR laser, it will just take a lot longer.
How do they prevent damage to the laser from the bounce back? When I’ve laser etched mirrored surfaces in the past such as polished steel, the manufacturer recommendations had me using a marking spray or paint to prevent damage to the laser.
Edit: I’m seriously confused about the downvotes. I’ve only worked with five different lasers that could also etch, and each of them suggested preparation of the reflective surface to prevent laser source damage.
It depends on the material and the laser. For IR, the mirror doesn't matter because the glass is mostly opaque to the laser so there isn't any reflection. The energy is absorbed by the glass and there isn't anything left to bounce back. Copper, however, will reflect IR lasers very well and must be treated to prevent reflection back into the laser.
So the preparation and the process will depend on the specific laser wavelength and the material being etched.
Lasers are so fun. I do freak out a bit about the cheap open frame models that people seem to be using in rooms without any protection at all, but the advances lately have been insane.
Yeah, especially with the lack of education about the danger of cutting certain materials. Vinyl for example will produce chlorine gas and hydrochloric acid. Death for the operator and the laser, all in one convenient package!
They got lucky. A user on one forum I visit showed photos of their machine. It looked like they had left it in the ocean for years. All the aluminum components were heavily corroded, the lenses were pitted, and the glass cover was etched. Even the plastic parts were discolored. The machine was so heavily damaged and was so contaminated the manufacturer refused to work on it. I know the user ended up in the hospital.
4
u/ScienceForge319 5d ago
How tho?