[MrC11111]

Hello

A way to make laser light in Maxwell Studio, or maybe in the next V4 ?

[seghier]

you can with motion blur
create for example small sphere
move it between two points than activate motion blur

[MrC11111]

Smart
So it seems that laser is not yet in the v3, damned, maybe for the future!?
When you think that you can buy a green laser light in real life for $15..

[bograt]

This is using maxwells projector feature and volumetrics.
you could make an enclosure to keep the beam near parallel along its length.
This was sl23 and there is still a fair bit of noise in the reflected areas, this is mainly because the source of reflected light is so small. Any smaller and the render times will increase yet more.
I would do something in post if I were you.