The gain bandwidth of the erbium-doped fiber amplifier limits the enhancement of the transmission capacity in optical fiber communication systems. This Letter reports an erbium-ytterbium co-doped phosphosilicate fiber, which is expected to increase transmission capacity by extending the L-band gain bandwidth to 1623 nm. The fiber was fabricated by modified chemical vapor deposition combined with solution doping technology. The mechanism of bandwidth-expansion by inhibiting the signal excited-state absorption was investigated. When the signal power and pump power were maintained at ${-}{3.7}\;{\rm{dBm}}$ and ${\sim}{{720}}\;{\rm{mW}}$ at 1480 nm, the 20 dB gain range was extended out to 1623 nm. Additionally, the noise figure at 1623 nm decreased to 6.01 dB, with 23 dBm saturated output power. The results show that the erbium-ytterbium co-doped phosphosilicate fiber has a great potential for extending L-band amplification.

中文翻译：

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使用 Er/Yb/P 共掺杂磷硅酸盐光纤将 L 波段放大扩展到 1623 nm

掺铒光纤放大器的增益带宽限制了光纤通信系统传输容量的提高。这封信报道了一种铒镱共掺杂磷硅酸盐光纤，该光纤有望通过将 L 波段增益带宽扩展到 1623 nm 来提高传输容量。该光纤是通过改进的化学气相沉积结合溶液掺杂技术制造的。研究了通过抑制信号激发态吸收来扩展带宽的机制。当信号功率和泵浦功率保持在${-}{3.7}\;{\rm{dBm}}$和${\sim}{{720}}\;{\rm{mW}}$在 1480 nm 处，20 dB 增益范围扩展到 1623 nm。此外，1623 nm 处的噪声系数降低至 6.01 dB，饱和输出功率为 23 dBm。结果表明，铒镱共掺磷硅酸盐光纤在扩展L波段放大方面具有很大的潜力。