Low cost high-order Raman amplifier assisted enhanced remotely pump amplifier technology for ultra-long span OTN system

Abstract In this paper, a 420 km Optical transport network (OTN) transmission system of 8 × 100 Gbit/s signals was achieved with amplifier combination of a low cost second order Raman amplifier and an enhanced remotely pump amplifier. The second order Raman amplifier consist of a commercial first order Raman amplifier and two auxiliary lasers which is completely controlled by the first order Raman amplifier. The total link budget is 84 dB with a power margin of more than 4 dB. The new amplifier structure increased the link power budget by 6.5 dB and OSNR by 1.4 dB on average.