Guo Ying, Li Jianshe, Li Shuguang, Zhang Shuhuan, Liu Yundong
Appl Opt. 2018 Sep 20;57(27):8016-8022. doi: 10.1364/AO.57.008016.
In this paper, a D-shaped photonic crystal fiber is designed to achieve a single-polarization filter that has a broadband filtering property. The D-shaped structure is a triangular array of air holes, forming a micro-opening on the side-polished surface and plating a gold layer thereon. The investigation of the polarization filter is based on the finite element method; its principle is surface plasmon resonance. The single-polarization filter in the y direction is realized by adjusting parameters such as the apertures of the fiber, the thickness of the gold layer, and the polishing depth. The confinement loss of the core mode in y polarization reaches to a high value of 376.31 dB/cm at 1.55 μm, and that of the x polarization is 0.17 dB/cm; the former is 2225.35 times the latter. When the fiber length L is 1 mm, the crosstalk reaches a peak value of 326.7 dB at 1.55 μm, and the bandwidth of crosstalk higher than 20 dB is 480 nm. In addition, the external gold coating operation is more conducive to application in the manufacturing process. This filter will be an effective application of the optical communication window near 1.55 μm.
本文设计了一种D形光子晶体光纤，以实现具有宽带滤波特性的单偏振滤波器。D形结构是气孔的三角形阵列，在侧面抛光表面上形成一个微开口并在其上镀上一层金。对偏振滤波器的研究基于有限元方法；其原理是表面等离子体共振。通过调整光纤孔径、金层厚度和抛光深度等参数来实现y方向的单偏振滤波器。在1.55μm处，y偏振的纤芯模式的限制损耗达到376.31dB/cm的高值，而x偏振的限制损耗为0.17dB/cm；前者是后者的2225.35倍。当光纤长度L为1mm时，在1.55μm处串扰达到326.7dB的峰值，高于20dB的串扰带宽为480nm。此外，外部镀金操作在制造过程中更有利于应用。该滤波器将有效应用于1.55μm附近的光通信窗口。
