Effect of saturation tone on spectral EDFA gain spectrum

• Published in: Measurement : journal of the International Measurement Confederation 2025-02, Vol.241, p.115724, Article 115724
• Main Author: Durak, Firat Ertac
• Format: Article
• Language: English
• Subjects: Erbium-doped fiber amplifier; Saturation tone; Spectral gain measurement; WDM systems
• ISSN: 0263-2241
• DOI: 10.1016/j.measurement.2024.115724

•A measurement method for characterizing the spectral gain of C-band EDFAs is investigated in detail using a saturation tone and a weak signal probe with simulation and experimentally.•It is a cheaper alternative to conventional techniques that require expensive WDM equipment.•The ideal saturation tone wavelength depends on the configuration (forward or bidirectional) and the pump wavelength (980 nm or 1480 nm), but a good fit can be achieved in any scenario, particularly at higher saturation levels.•This measurement method provides researchers and engineers with a useful tool for developing affordable EDFA gain measurement techniques. Accurate characterization of spectral gain of C-band EDFAs in WDM system design is crucial; however, traditional methods often require expensive WDM equipment. This study presents a cost-effective alternative, validated through both experimental measurements and simulations, that utilizes a weak signal probe and a carefully selected saturation tone. By comparing results with a 32-channel WDM reference, we demonstrate that the proposed method achieves high accuracy. The optimal saturation tone wavelength depends on the pump wavelength (980 nm or 1480 nm) and configuration (forward or bidirectional). Nevertheless, a good fit with the reference can be obtained in all scenarios, especially at higher saturation levels. This work provides valuable insights for developing affordable and efficient EDFA gain measurement techniques.