A long single-span dispersion-decreasing-like fiber transmission system

Abstract

We propose a novel unrepeated long single-span front-haul transmission system based on dispersion-decreasing-like fibers (DDLF). The modulation format is 160Gbps and PM-16QAM. The system transmission performance is effectively improved due to the balance of dispersion and nonlinear effects by using the DDLF, the balance of Raman amplification power and input optical power induced by equalization amplification between Raman amplifier and EDFA. The proposed system can effectively avoid the time delay of signal because of low dispersion of the DDLF system, and compensate the transmission attenuation impairment by employing the first-order Raman amplification at lower input power. The bit error rate (BER) of the system is better than 7% hard-decision forward error correction (FEC) threshold value of 3.8 × 10−3 in a wide range of input optical power. This system can be used in the long single-span front-haul transmission in special application scenarios. At higher input optical power, the nonlinear effect of the DDLF is the dominant factor affecting the performance of the transmission system, and nonlinear effect of the DDLF is increased with the increase of input optical power and Raman pump power, resulting in the system performance deterioration.