Study on the Impact of Nonlinearity and Noise on the Performance of High-Capacity Broadband Hybrid Raman-EDFA Amplified System

Abstract

We experimentally demonstrated the transmission of 312⇥35 GBd DP-256QAM over 9⇥70 km spans using hybrid distributed Raman-EDFA (HRE) amplifiers with a continuous 91 nm gain bandwidth. A total throughput of 120 Tbit/s over 630 km is demonstrated, with a net achievable information rate after SD-FEC of 10.99 bit/symbol. An extensive, theoretical investigation of the noise contributions originating from amplifier, transceiver sub-system and fiber nonlinearity were carried out using the Gaussian noise model in the presence of inter-channel stimulated Raman scattering (ISRS GN model). The ISRS GN model accounts for arbitrary, wavelength dependent signal power profiles along fiber spans, which is vital for the modeling of ultra-wideband transmission, particularly for hybrid Ramanamplified links. The analysis serves to quantify the relative noise contributions and explain the performance achieved. It was found that, due to the low noise HRE amplifier and a transmission distance of 630 km, the noise originating from the transceiver sub-system imposed a penalty of 6 dB in SNR. For this system, the transceiver noise is, therefore, the main limitation to the system throughput.Index Terms-Hybrid Raman-EDFA amplifier, broadband transmission system, high order modulation format, adaptive rate LDPC decoder.

Optical Fibre Capacity Optimisation via Continuous Bandwidth Amplification and Geometric Shaping

“…Nevertheless, by combining an SOA with distributed backward Raman amplification, 107 Tbit/s transmission over 300 km (3⇥100 km) was reported in [4]. A yet greater data rate of 120 Tbit/s over 630 km (9⇥70 km) was shown by using hybrid distributed Raman-EDFA amplifiers with a continuous 91 nm gain bandwidth [5]. Extending the transmission bandwidth to S-band wavelengths resulted in the highest single mode fibre capacity experimentally shown to date of 150.3 Tbit/s, transmitted over 40 km [1] This experiment [1] used a distributed backward Raman amplification scheme for the S-band and EDFAs for C-and L-bands; with the transmitted signal occupying a total bandwidth of approximately 109 nm (13.625 THz).…”

Candidate Technologies for Ultra-wideband Nonlinear Optical Fibre Transmission System

“…capacacity transmission systems Several milestones of record data throughput using single mode fibre (SMF) [1][2][3][4][5][6][7][8][9][10][11][12] have been reported over the last few years. Fig.…”

“…Through the combination of SOA and distributed backward Raman amplifier, 107 Tbit/s transmitted over 300km (3x100km) was demonstrated in [9]. Higher data throughput of 120 Tbit/s over 630 km (9x70km) was achieved by using continuous 91 nm hybrid distributed Raman-EDFA amplifier [10] [11]. Can be noted that by using hybrid Raman/EDFA amplifier, the data throughput and distance are both increased over SOA/Raman amplification scheme, with an extra 13 Tbit/s capacity over more than 3 times longer transmission distance, whistle using 12 nm less transmission bandwidth.…”

“…Furthermore, non-ideal digital signal processing (DSP) at both the transmitter and receiver has an associated penalty that also constrains the transceiver SNR TRX i [14,15]. Fig.2: Signal-to-noise ratio including different noise components versus wavelength after 630 km [11]. Fig.3: Total signal-to-noise ratio versus distance for different transceiver noise.…”

“…The amplification scheme is hybrid distributed Raman-EDFA (HRE) amplifiers with a continuous gain bandwidth of 91 nm. A data throughput of 120 Tbit/s over a transmission distance of 630 km is reported in [10,11] for this transmission system under investigation. To estimate the nonlinear noise power per channel i, the Gaussian noise model in the presence of inter-channel stimulated Raman scattering [17] was used; details of the system under investigation and modelling can be found in [11].…”