分析布拉格光栅破坏的两纤芯不同的光纤耦合器

Analysis of Bragg Grating-Frustrated Dissimilar Two-Core Coupler

进一步推广了描述纤芯不同光纤耦合器的耦合模理论 ,用于解释被布拉格光栅破坏的两纤芯不同光纤耦合器的耦合现象 ,理论分析的结果与已报道的实验结果相符。与单独的布拉格光栅所起的反射作用不同 ,这里布拉格光栅所起的作用主要是引入了强烈的色散 ,在光栅的频谱范围内使耦合器不再同步。在被布拉格光栅破坏的光纤耦合器的选择性频谱中 ,其边缘部分出现非常弱的波动 。

The coupled mode theory for fiber coupler with dissimilar cores is extended to analyze the coupling phenomena in grating frustrated ones. The theoretical results are agreed well with the experimental results in references. Unlike the Bragg grating alone as reflective element, the main effect of the Bragg grating in the coupler is that it introduces a strong dispersion, making the coupler asynchronous in the spectral band of grating. It is also found that the selective spectra of the Bragg fiber coupler caused by the Bragg grating frustrated in the two dissimilar core fiber have not any sidelobe but have very weak jitters on the spectral side part and strong dips on the spectral stop band.