Output power characteristics of C+L‐band erbium‐doped superfluorescent fiber source

A new type double‐stage double‐pass configuration of the erbium‐doped superfluorescence fiber source (EDSFS) is designed and realized experimentally based on the numerical simulation and theoretical analysis.The principle of L‐band superfluorescence of erbium‐doped fiber (EDF) is investigated. Numerical simulation and theoretical analysis of the L‐band output spectrum of double‐pass forward EDSFS is carried out. In this configuration, the first stage of the EDSFS emits L‐band superfluorescence through high‐doped Er 3+ concentration, and the backward pumping generates C‐band superfluorescence by low‐doped Er 3+ concentration. By optimizing the configuration parameters such as the length of two different concentrations of EDF and the forward and backward pump power, the output power of 9.2 mW, spectrum bandwidth of 65 nm with flatness of 2.5 dBm, and mean wavelength of 1565.253 nm have been achieved.