Motorized Stages for smallest incremental movement possible?

[COLOR=#1D1D1D][FONT=&quot]I've got a project where I need to move a laser into a detector about 100m away and need to find some motorized stages with the smallest possible incremental movements. The whole package will need to be pretty small, probably no bigger than the size of a bread box. The motorized stages will be controlled by an auto alignment software, not sure what the controller will be, either raspberry pi or a micro form factor PC. Any suggestions for which motorized stages I should use? Thanks[/FONT][/COLOR]

Stepper motor mechanism and an electronics engineer.