Demonstrate the process of detecting the fiber jumper end face, 3D interferometer, insertion loss and return loss at the test bench. All optical fiber jumpers of LiTian (LT) must be fully tested by the test bench, among which the 3D interferometer is mainly used for testing MTP/MPO fiber jumpers, and the IL and RL tests are mainly for conventional optical fiber jumpers, Uniboot jumpers and armoring. Jumper.