Power Consumption Analysis of Hybrid EDFA/Raman Amplifiers in Long-Haul Transmission Systems

We analyze the power consumption of optical amplifiers and the tradeoff between power consumption and system performance. The power consumption model includes erbium-doped fiber amplifiers (EDFA), backwards pumped Raman amplification, and monitoring and management electronics. Performance is studied using the Gaussian-noise model for nonlinear interference. We find that the power consumption of the monitoring and management electronics has a large impact on system configuration that gives the lowest overall power consumption, where a low value favors shorter spans and EDFA-only amplification, while a high value favors longer spans with Raman amplification. Long total system lengths and high requirements on the optical signal-to-noise ratio also favors Raman amplification. Furthermore, we compare the amplifier energy consumption per bit for polarization-multiplexed quadrature phase-shift-keying and 16-quadrature amplitude modulation (16QAM). Our results show that 16QAM has a lower energy consumption per bit due to its higher spectral efficiency. We also find that it may be more energy efficient to increase the signal quality by shortening the spans or using Raman amplification than using powerful forward error correction with high power consumption.