The gain and noise figure comparison of single-pass, double-pass, and dual-stage triple-pass thulium-doped fiber amplifiers in S-band with thulium-doped fiber optimization

摘要

This study presents a comparison of three different S-band thulium-doped fiber amplifiers (TDFA) designs. The gain performances of the amplifiers are analyzed based on each scheme, separately. With -20 dBm input power, to provide ground-state and excited-state absorptions, the 1050 nm pump is used in all designs. The thulium-doped fiber (TDF) lengths are optimized for maximum gain by using the single parameter single result optimization of Optisystem 18.0 software. A reflector is integrated into the double-pass and dual-stage triple-pass TDFA to allow double propagation. Compared to double-pass TDFA, in dual-stage triple-pass TDFA design, gain values increased without changing the stable bandwidth. 42.77 dB gain is demonstrated for two optimized TDF lengths; L1: 5 m and L2: 4.8 m, while noise figure values are higher than the other schemes. This comparison is important to show that the dual-stage triple-pass TDFA design could be suitable for obtaining higher gain in wider stable bandwidth in the fiber optic communication systems.