So i'm trying to build this sci-fi looking scene and trying to scan one of my model but it won't give a decent result I tried using sun lamp reducing its size and blocking it with plane having a narrow slit. Here's the link of something similar
I would use a really low poly cylinder in the shape of the beam (no edge loops between the start and end of the beam), two bones, one for the start of the beam and one on the object its hitting with an emission shader on the mesh.
If you enable 'emission' under Layers/Passes you can control how it glows in the compositor. https://www.youtube.com/watch?v=TwAksU_hBFM is a fun tool for that. Thanks to BlenderBrit.