Research on the novel hybrid amplifier based on Raman and ZBLAN-TDFA

For S-band wavelength division multiplexing (WDM) systems, the
$\text{ZrF}_{4}-\text{BaF}_{2}-\text{LaF}_{3}-\text{AlF}_{3}-\text{NaF}$
based thulium doped optical amplifier (ZBLAN-TDFA) is a main amplifying media. However, the main limitation of TDFA is the low gain and lack of gain flatness, which requires Raman amplifier (RA) to compensate for its shortcomings. In this paper, the gain is achieved by using a hybrid optical amplifier (HOA) composed of a RA and ZBLAN-TDFA. The effects of variations in amplifier fiber length and RA pumping power on HOA gain were investigated.