Multi-Stage EDFA Amplifiers: Optimizing Gain and Noise Performance Across Fiber Lengths (10–24 m) in the 185.2–186.2 THz Band

This study presents a systematic evaluation of Erbium-Doped Fiber Amplifiers (EDFAs) across single- to five-stage configurations, addressing the critical need for high gain and low noise in next-generation optical networks. Leveraging OptiSystem simulations, we demonstrate that five-stage EDFAs achieve a peak gain of 36.60 dB and a record-low noise figure of -36.35 dB in the 185.2–186.2 THz range. By optimizing parameters such as erbium ion density (1,100 ppm-m), pump power (+23 dBm), and fiber length (10–24 m), our analysis reveals that extended multi-stage architectures significantly outperform single-stage designs, particularly at L=24 m. The 3D spectral analysis further highlights the interplay between gain stability and noise suppression, offering actionable insights for deploying EDFAs in long-haul, high-capacity communication systems. These findings advance the design of energy-efficient optical amplifiers, bridging a critical gap in terahertz-band network infrastructure.