METHOD AND DEVICE FOR MEASURING OPTICAL TRANSMISSION LOSS OF OPTICAL FIBER SYSTEM

PURPOSE:To simplify measuring operation and to save the labor cost and time required for reconnecting operation by connecting three optical branching devices and obtain four measurement light beams. CONSTITUTION:The three optical branching devices 6, 8, and 9 are stored in a case 1 which has a single input terminal 2 and four output terminals 5. The input side 6a of the optical branching device 6 is connected to the terminal 2 through an optical fiber cord 7 and output sides 6b and 6b are connected to the input sides 8a and 9a of the optical branching devices 8 and 9 through optical fiber cords 10 and 11. Further, the output sides 8b and 8b, and 9b and 9b of the optical branching devices 8 and 9 are connected to the four terminals 5 through the optical fiber cords 12, 13, 14, and 15. Then, light from a single light source is inputted to the terminal 2 through a dummy fiber and then the input light is outputted from the terminals 5 as four measurement light beams through the optical branching devices 6, 8, and 9. The terminals 5 are connected to the core of an optical fiber cable to be measured and then output light beams having the same light intensity can be sent to the four cores at the same time.