不同泵浦方式下Er3 /Yb3 共掺光纤放大器的自发辐射谱

用改进的MCVD法和湿法掺杂技术设计制作了2种不同Er^3＋、Yb^3＋浓度比的Er^3＋／Yb^3＋共掺光纤（EYDF），利用980nm和1480nm泵浦LD对Er^3＋／Yb^3＋共掺光纤放大器（EYDFA）的放大自发辐射（ASE）谱进行了研究。利用980nm LD泵浦时，这2种光纤在C波段的ASE强度都很弱，吸收系数小的EYDF在C波段的荧光强度比吸收系数大的光纤大2个量级。用1480nmLD对吸收系数大的EYDF进行泵浦，优化光纤长度，此时C波段荧光强度比用980nm泵浦时大5个量级。这是由于对于EYDF在976nm附近Yb^3＋有很强的非饱和吸收，导致能量传输效率差，因此980nmLD不适合做高浓度EYDFA的泵浦源。而1480nm泵浦时，Yb^3＋不再作为敏化剂而只起到克服成对Er^3＋间的浓度淬灭问题，同时起到提高Er^3＋在石英基光纤中的溶解度的作用。

Amplified Spontaneous Emission of Er3 /Yb3 co-doped Fiber Amplifier with Different Pump Lasers

Two Er~(3+)/Yb~(3+) co-doped fibers with different ion ratio were fabricated through the MCVD and solution doping method.We explored the amplified spontaneous emission(ASE) of Er~(3+)/Yb~(3+) co-doped fiber amplifier(EYDFA) with 980 nm and 1 480 nm pump schemes.The measurement results showed that ASE spectrum was very weak when the pump light wavelength was near 976 nm.The EYDF with low absorption coefficient has higher intensity than that with high absorption coefficient.This unexpected result is caused by Yb~(3+) unsaturable absorption and low energy transfer efficiency when pump wavelength is at 976 nm.But the ASE intensity of EYDFA pumped by 1 480 nm LD is strong,which is about 5 orders of that pumped by 980 nm LD.