The National Institute of Information and Communications Technology (NICT) has succeeded in a transmission experiment of 273.6 terabits per second over 1000 km using the first amplified repeater on a 15-mode optical fiber. As a result, it is said that the way of utilization in land communication infrastructure will be greatly expanded.
Although multimode optical fiber transmission can achieve large capacity in combination with wavelength division multiplexing technology, long-distance transmission was difficult. In this research, NICT built a loop transmission experimental system including 15 parallel amplification repeaters that cover the entire C-band (commercial wavelength band), and a method that switches the mode for each optical signal during amplification and repeats. was developed for 15 modes, the time difference between paths of each optical signal after transmission was suppressed, and a transmission distance of 1001 kilometers was realized.
The amplified repeater transmission system in this experiment can also be applied to coupled multi-core optical fibers suitable for long distances, and it is expected that further increases in capacity and distances will be realized in the future.