放大自发辐射辅助泵浦的L波段扩展掺铒光纤放大器

L-Band Extended EDFA Co-Pumped by Backward ASE

近年来,L波段扩展的掺铒光纤放大器(LE-EDFA)由于能增加光纤传输带宽而成为研究热点,但该放大器所需增益光纤较长,普遍存在泵浦转换效率低、增益水平不高等问题。将反向放大自发辐射(ASE)辅助泵浦技术应用于LE-EDFA增益提升研究,发现反向ASE在泵浦功率较低或铒镱共掺光纤(EYDF)较长的情况下,可以大幅度提高LE-EDFA的增益水平,提高量可达5.1 dB~16.7 dB。采用反向ASE辅助泵浦结合预放大技术,在550 mW的较低总泵浦功率情况下,实现了1570~1610 nm范围内高于20 dB的增益、低于6 dB的噪声系数,并且1620 nm处的增益尚达13.7 dB。与其他已报道LE-EDFA相比,反向ASE辅助泵浦的LE-EDFA在较低的泵浦功率情况下实现了等同的增益水平,具有泵浦转换效率高、制备成本低等优势,有望广泛应用于高容量光纤传输系统。

Lband extended erbiumdoped fiber amplifiers(LEEDFA)have been studied in recent years for their extended gain bandwidths.However,the pump conversion efficiency and gain level are generally low due to the relatively long gain fiber required for this amplifier.In this paper,we improve the gain level of LEEDFA by employing the backward amplified spontaneous emission(ASE)copumping technique.It is found that gain level improvement up to 5.1 dB‒16.7 dB can be achieved in the wavelength range of 1570‒1620 nm when the pump power is relatedly low or the Er/Yb codoped fiber(EYDF)is relatively long.We then use the backward ASE copumping technique in a preamplified LEEDFA and achieve a 20 dB gain bandwidth covering 1570‒1610 nm and noise figure less than 6.0 dB at a relatively low pump power of 550 mW.And the gain at 1620 nm is 13.7 dB.Compared with other reported LEEDFAs,the Lband extended EDFA copumped by backward ASE achieves the same high gain level at the lowest pump power.The extended gain bandwidth,high pump conversion efficiency and low cost make it very prospective in highcapacity optical transmission systems.