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【研究进展】基于模式-频率映射技术测量少模光纤的模式分布

发布时间:2018-03-22 11:58

  少模光纤具有很大的潜力作为光通信的一种新的传输介质,因此区分光纤中不同模式的能力是很重要的。大多数传统的方案都不能获取模式的相位信息,或者受限于光斑尺寸和机械要求。考虑到现有测量技术的不足,发展一种简单的、能够同时测量光纤模式的幅度和相位分布的测量方法是非常迫切的。
      武汉光电国家研究中心光电子器件与集成功能实验室张新亮教授、董建绩教授和周海龙博士等人提出了一个基于模式-频率映射的模式分析仪。该方案可以同时测量到少模光纤中模式的幅度和相位分布。通过动态的相位板,光纤模式被映射到频率上。从频率信息可以恢复光纤模式的相对幅度和相位信息。我们利用两模光纤开展了相应的实验,并且验证了方案,其实验装置图和模式变化过程如图1所示。该方法不仅可以得到光纤模式的幅度分布,还可以得到相位分布,并且不需要额外的辅助光,使得系统稳定、操作简单。
       2018319,美国光学学会(OSA)旗下期刊《光学快报》(Optics Letters)上在线刊发了该研究成果。该研究成果获得了国家自然科学基金(Grant No. 6162250261475052)的支持,发表的文章全文链接为:
http://ol.osa.org/abstract.cfm?URI=ol-43-7-1435 

1:(a)实验装置图和(b)模式变化过程


Mode measurement of few-mode fibers by mode-frequency mapping
Since few-mode fibers have great potential as the new transmission media for optical communications, the ability to distinguish different fiber modes is essential. Most of the traditional schemes do not yield phase information, or are limited by beam size and mechanical requirements. In light of the shortcomings of the measurement techniques, it is still desirable to develop a simple method that enables simultaneous measurements of the amplitude and phase distributions of fiber modes.  
Several researchers in Wuhan National Lab for Optoelectronics, including Prof. Xinliang Zhang, Prof. Jianji Dong, and Dr. Hailong Zhou, etc. have put forward a method to measure the power and phase distribution of fiber modes in FMFs. The fiber modes are mapped to different frequencies by using dynamic phase masks. We can retrieve the relative amplitude and the relative phase of fiber modes from the frequency content. An experiment is carried out to demonstrate the scheme by using a two-mode FMF. The experimental setup and the evolutionary process of modes are presented in Figs. 1(a) and 1(b). The method can not only extract the amplitude distribution but also the phase distribution of the fiber modes, and no reference light is required, making the system stable and simple.
This work has been on-line published in Optics Letters on 19 March 2018 [1]. Relative work was partially supported by National Natural Science Foundation of China (61622502 and 61475052). Full text can be viewed by



Fig.1. (a) Experimental setup for the measurement of fiber mode distribution. (b) The used phase masks and measured patterns.