To compute laser power density (power/unit area or irradiance), we will need a value for the diameter of the beam coupled with the value of the fraction of total power transmitted within that diameter. Average power and power density can be easily calculated here or here.
LiDAR (light detection and ranging) can measure the distance of an object (measuring the time for the reflected light beam to return to the receiver) using pulsed lasers. It also can create a 3D image of an object.