Pump Power Depreciation by Photodarkening in Ytterbium-Doped Fibers and Amplifiers
Pump Power Depreciation by Photodarkening in Ytterbium-Doped Fibers and Amplifiers
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DOI：
10.1109/lpt.2013.2289965
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发表时间：
2014
影响因子：
2.6
通讯作者：
Nanxi Li;S. Yoo;Xia Yu;D. Jain;J. Sahu
中科院分区：
文献类型：
--
作者：
Nanxi Li;S. Yoo;Xia Yu;D. Jain;J. Sahu
本文研究了掺镱光纤（YDF）中由于光暗化效应引起的泵浦功率衰减。通过同时测量可见光和泵浦波长处的透射功率来监测光暗化，这使得直接定量测量泵浦功率降低而不是过量的背景损耗。我们观察到光暗化光纤中泵浦功率的显著降低和荧光衰减时间的缩短，表明光暗化影响泵浦效率。通过观察实现相同YDF的YDF放大器的性能，还研究了器件级的光暗化效应。通过数值模拟定量研究了这种光纤放大器的泵浦功率衰减。结果表明，在一个饱和的制度，有助于制服的光暗化，与解释提供的粒子数反转密度。计算出的功率衰减水平为15%-30%，这与我们的实验观察相符。
In this letter, pump power depreciation due to photodarkening effects in an ytterbium doped fiber (YDF) is investigated. Photodarkening is monitored by measuring the transmitted power at visible and pump wavelengths simultaneously, which renders direct quantitative measurement of pump power reduction rather than excess background loss. Our observation of substantial reduction in the pump power and the shortened fluorescence decay time in the photodarkened fiber indicates that the photodarkening influences pump efficiency. The effect of the photodarkening in a device level is also investigated by observing the performance of the YDF amplifier implementing the same YDF. The pump power depreciation of this fiber amplifier is quantitatively investigated by numerical simulation. The results suggest that operating at a saturated regime helps to subdue the photodarkening, with explanation in terms of population inversion density provided. The level of power depreciation is calculated to be 15%-30%, which matches our experimental observation.