At the moment, I am trying to minimize the cross scan error and improve the resolution.
My work has allowed me to build as setup, so I can improve the optics.
So far I have figured out that I can change the diode position. At the edges, the reflection is about 40 percent. The spot you see on the screen is the pulse send to the photo-diode. It reflects and transmits at the same time. I plan to use the space created, to add cylindrical lenses.