Orientation and centering of a laser beam IR or visible are necessary in its various applications.
In the cases where a visual rapid positionning of the laser beam is more important than an extreme
precision, the system proposed here presents advantages described in what follows.
"Liquid-crystal display for centering a laser spot", Proc. SPIE 1319, Optics in Complex Systems, (1 July 1990); doi: 10.1117/12.34911; https://doi.org/10.1117/12.34911