Sun Zhoulu, Liu Yan-ge, Wang Zhi, Tai Boyin, Han Tingting, Liu Bo, Cui Wentao, Wei Huifeng, Tong Weijun
Key Laboratory of Opto-Electronic Information and Technology, Ministry of Education and Institute of Modern Optics, Nankai University, Tianjin, China.
Opt Express. 2011 Jul 4;19(14):12913-8. doi: 10.1364/OE.19.012913.
A novel in-fiber modal interferometer based on a long period grating (LPG) inscribed in a two-mode all-solid photonic bandgap fiber (AS-PBGF) is presented. After inserting a small piece of the AS-PBGF into two sections of standard single-mode fiber (SMF) via being spliced slight core offset, LPG is inscribed in the AS-PBGF. The LPG is especially designed to realize the coupling between two core modes of LP01 and LP11 in the AS-PBGF. Two core modes LP01 and LP11 of the AS-PBGF are excited firstly at the input spliced point and actualized energy exchange when they pass through the LPG. Then the two beams will interfere at the output spliced point to form a high-contrast in-fiber modal interferometer. The proposed interferometer has some advantages such as configuration compact, high interference contrast and the wavelength spacing well controlled by changing the position of the LPG without changing the total length of AS-PBGF.
提出了一种基于写入双模全固态光子带隙光纤（AS-PBGF）中的长周期光栅（LPG）的新型光纤模态干涉仪。通过轻微芯偏移熔接将一小段AS-PBGF插入两段标准单模光纤（SMF）中后，在AS-PBGF中写入LPG。该LPG经过特殊设计，以实现AS-PBGF中LP01和LP11两个芯模之间的耦合。AS-PBGF的两个芯模LP01和LP11首先在输入熔接点被激发，并在通过LPG时实现能量交换。然后这两束光将在输出熔接点处干涉，形成高对比度的光纤模态干涉仪。所提出的干涉仪具有一些优点，如结构紧凑、干涉对比度高，并且通过改变LPG的位置可很好地控制波长间距，而无需改变AS-PBGF的总长度。
