Multi-band Ge20Sb15Se65 dual-core photonic crystal fiber polarization beam splitter with filled liquid crystal
摘要
In this paper, a novel multi-band Ge20Sb15Se65 glass-based dual-core photonic crystal fiber polarization beam splitter (DC-PCF PBS) with filled liquid crystal has been proposed. Based on the DC mode coupling theory and the full vector finite element method, the characteristics of the proposed DC-PCF PBS are calculated and analyzed, and the cores A and B have three different splitting bandwidths (SBs), respectively. When the splitting length (SL) is 7687 μm, the SBs of the cores A and B are 21 nm (1.415–1.436 μm), 23 nm (1.574–1.597 μm), and 13 nm (1.707–1.720 μm), and 29 nm (1.354–1.383 μm), 16 nm (1.577–1.593 μm), and 15 nm (1.733–1.748 μm), respectively. The total SBs of the cores A and B can reach 57 nm and 60 nm, respectively. The maximum insertion losses (ILs) of the X-pol and Y-pol in the different SBs are 1.31 and 0.88 dB, respectively. By introducing the fabrication process of the proposed DC-PCF PBS, the limitations and requirements of the current fiber testing process on the actual SL are analyzed and discussed. The structural characteristics, splitting bandwidth, max IL and other performance are compared with the results reported in recent years. Finally, a novel DC-PCF PBS with simple structure, multi-band polarization splitting, wide total SB, low IL, and more suitable SL for practical testing techniques is obtained. It not only works in the second near-infrared (NIR-II) window (900–1900 nm) but also has the advantages of simple fabrication, a wide application range, abundant bandwidth resources, high practicality, and easy integration with all fiber networks. This DC-PCF PBS may play a key role in fields such as single polarization fiber lasers, polarization sensitive optical coherence tomography (OCT), and fiber optic biosensors. In addition, it has the potential to play an indirect role in biophotonics fields such as OCT based animal neuron activity monitoring.