Optimizing active fiber lengths in different pump ratios of hybrid wavelength pumped fiber amplifier

At present, fiber amplifiers are generally pumped by fiber-coupled semiconductor laser with a wavelength of 915nm or 976nm. With fast development of application field, the requirement of pump injection power is becoming higher and higher, single-band pumping may not meet practical requirements in high-power fiber laser applications. The total power of the pump source can be greatly increased by combining the 915nm and 976nm pump sources with spectral bundling technology. Based on this, the gain fiber length of hybrid wavelength pumped fiber amplifiers at 915nm and 976nm was optimized under different pump power ratios. By usingSeeFiberLaser software, we investigated the relationship between pump power ratio and output power, efficiency, residual pump power, Raman power and the length of active fiber. This paper has some guiding significance for choosing the pump power ratio and gain fiber length of mixed wavelength pump fiber amplifier.