When working with manipulators in the fields, it is necessary to have 3D information of the work object and its surroundings. When the manipulator is applied to radiation fields, it is necessary to protect the measurement devices, for example, the LiDAR from radiation in its environment. To enforce radiation resistance of the LiDAR, a radiation shielding container for it the LiDAR is developing, in Mitsubishi Heavy Industries, Ltd., with design of labyrinth with conical mirrors to make passes from/to the LIDAR. For the geometrical system formed by labyrinth with conical mirrors, Laser pass analysis were executed and reported.