Tony,
First I will answer you questions...
- It is suitable to engrave stainless steel?
NO
- Is it dangerous if the beam gets reflected from the steel?
YES
- If is dangerous, is any way to filter the reflected beams?
YES (glasses or laser shield for 808nm)
- Any way to control the diameter of the marking point?
YES (focus lens and distance, but reduced power at larger spot size)
- Is any way to control the power output of the laser? Due to prevent getting trough (cut?) the borders of the material?
YES (input current and/or TTL pulse width will control output power, but since it won't do anything to the stainless steel you won't need to worry about cutting through)
- What about the focus of the laser? :O?
Lens / Z-height
- Is any way to control it from Mach3 like a plasma torch? :O?
Yes, the same as a torch control (plug in for laser is available)
- In the case that it is siutable, what ranges of speeds work for engraving?
Not suitable except for engraving on paper/wood or cutting thin wood or some plastics
Now, what you probably want to know... how to achieve the results shown in your pictures. They are most likely done using an additive process and CO2 laser, research Cermark http://www.ferro.com/Our+Products/Co...rkets/CerMark/ LMM6000 or similar (it's sold under several brand names).
It isn't cheap, but the results are very good.
Zax.