Numerical study of Raman fiber amplifier based on cascading As-S fiber and As-Se fiber.

An optimal gain-flattened lumped Raman fiber amplifier (L-RFA), which was designed by cascading different chalcogenide fiber, was proposed and numerically demonstrated. The As-S fiber and the As-Se fiber were pumped by laser with different wavelengths. By solving the equation of the L-RFA, the characteristics including the gain and gain flatness of L-RFA are investigated. The results show that the L-RFA pumped by dual wavelengths can provide gain-flattened band from 1544 to 1558.4 nm with 0.0293 km fiber. Moreover, the average gain and gain flatness are 26.083 and 0.173 dB, respectively. The factors which influenced the output characteristics of L-RFA were also analyzed. [ABSTRACT FROM AUTHOR]