J4 ›› 2012, Vol. 29 ›› Issue (3): 303-310.

• 激光技术与器件 • 上一篇    下一篇

少模光纤放大器模式竞争及信噪比的研究

刘庆 魏安昆 郑睿 王安廷 许立新 明海   

  1. 中国科学技术大学光学与光学工程系, 安徽 合肥 230026
  • 收稿日期:2011-04-28 修回日期:2011-05-06 出版日期:2012-05-28 发布日期:2012-05-22
  • 通讯作者: 许立新(1966-)博士,副教授,主要研究方向是光纤通信子系统与器件,非线性光纤光学,超高速信号处理,光纤激光器和放大器等。 E-mail:xulixin@ustc.edu.cn
  • 作者简介:刘庆 女,硕士,主要从事高功率光纤激光器及放大器的研究。E-mail:luetsing@mail.ustc.edu.cn
  • 基金资助:

    NSAF联合基金(10876038)

Transverse mode competition and signal to noise ratio in few-mode fiber amplifiers

LIU Qing, WEI An-kun, ZHENG Rui, WANG An-ting, XU Li-xin, MING Hai   

  1. Department of Optics and Optical Engineering, University of Science and Technology of China, Hefei 230026, China
  • Received:2011-04-28 Revised:2011-05-06 Published:2012-05-28 Online:2012-05-22

摘要:

将信号模场和增益离子横向分布函数引入功率传输方程,采用多环法计算少模光纤放大器中信号及ASE的传输放大。研究增益离子分布对模式竞争和信噪比(SNR)的影响。对照模型改进前后结果,给出两种模型各自适用范围。结果表明,信号填充因子是表征不同模式在竞争中强弱地位的有效指标。增益离子集中掺杂有利于基模的放大和高阶模的抑制;集中均匀掺杂60%-70%较利于基模选择;随着掺杂范围趋于集中,ASE显著降低,信噪比逐渐提高。

关键词: 激光技术, 模式竞争, 分环法, 放大自发辐射, 功率填充因子

Abstract:

Transverse mode distribution and dopant profile are introduced in propagation-rate equations. An approximate numerical algorithm by multilayer method is presented to calculate the power of amplified signal and ASE in multimode fiber amplifiers. Numerical results of the propagation-rate equations before and after the improvement are compared. It shows that power filling factor is the key indication to describe the transverse mode competition behavior. Dopant profile makes great effect in mode selection and 60%-70% confinement of flat doping is more helpful in high-order mode suppression. ASE significantly dropped and SNR increased when the ions are doped more concentrated in the fiber core.

Key words: laser physics, transverse mode competition, multilayer method, amplified spontaneous emission, filling factor

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