A Structured Light Sensor (SLS) camera is one of the most high-tech pieces of ghost hunting equipment used by The Other Side team. The Xcam used by the team includes a wide variety of different functions: it sends a sonic signal out and bounces it back to itself to measure distance, it also measures temperature to help determine if there are significant differences in a room and includes a visual of the sound recording level which helps capture audio anomalies.
But its primary use is as a SLS camera which means it sends out thousands of points of little light to map an entire room or space. That light is either absorbed or bounced back directly to show a visualization of the room. The theory is that it can reveal things that might not be apparent to the naked eye. Presumably something like an apparition or ghost will affect light differently, so it might absorb or refract more light.
One cautionary note, the SLS Xcam can sometimes deliver a false positive if a physical object in a space bounces the light back in an unobvious way. So although our investigative team loves this tool, we always have to double and even triple check results that we get from it.