Abstract In this work it is proposed a novel all-fiber circular polarization beam splitter (CPBS). The design is based on helically twisted twin-core photonic crystal fiber coupler (HTTC-PCF). The main characteristic of the proposed CPBS device is the capacity to spatially split circularly polarized optical modes with opposite handedness at the twin-cores. For the CPBS to work, a single arbitrary rotated linearly polarized optical mode can be used as an input signal as well as a combination of two circularly polarized modes with opposite handedness. The coupling characteristics of HTTC-PCF were analyzed as function of the photonic crystal fiber (PCF) structural parameters, helical twist-rate, wavelength and temperature. The analyses were performed using a full vector finite element method with helical space mapping formalism and the supermode theory. An all-fiber CPBS with 24.76 mm length, extinction ratio ( ER ) of ~50 dB and spectral bandwidth of ~36.79 nm (for ER > 10 dB) and ~ 11.43 nm (for ER > 20 dB) was obtained at 1550 nm central wavelength for a twist-rate of 15.70 rad/mm.

中文翻译：

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基于螺旋绞合双芯光子晶体光纤耦合器的全光纤圆偏振分束器

摘要 在这项工作中，提出了一种新型的全光纤圆偏振分束器（CPBS）。该设计基于螺旋双芯光子晶体光纤耦合器 (HTC-PCF)。所提出的 CPBS 装置的主要特征是能够在双核处以相反的旋向性在空间上分离圆偏振光模式。为了使 CPBS 工作，可以使用单个任意旋转的线性偏振光模式作为输入信号，也可以使用两个具有相反旋向性的圆偏振模式的组合。HTTC-PCF 的耦合特性被分析为光子晶体光纤 (PCF) 结构参数、螺旋扭曲率、波长和温度的函数。使用具有螺旋空间映射形式主义和超模理论的全矢量有限元方法进行分析。在中心 1550 nm 处获得长度为 24.76 mm、消光比 (ER) 为~50 dB、光谱带宽为~36.79 nm（对于 ER > 10 dB）和 ~ 11.43 nm（对于 ER > 20 dB）的全光纤 CPBS扭转率为 15.70 rad/mm 的波长。