Short dual-core GaAs photonic crystal fiber splitter with a broad bandwidth and ultrahigh extinction ratio

Microstructured polarization beam splitters (PBSs) have attracted much interest in recent years. Here, a ring double-core photonic crystal fiber (PCB) PSB (PCB-PSB) with an ultrashort, broadband, and high extinction ratio (ER) was designed. The effects of the structural parameters on the properties were analyzed by the finite element method, which revealed that the optimal length of the PSB was 19.08877 µm and the ER was -324.257<i>d</i> <i>B</i>. The operating bandwidth for an ER of less than -20<i>d</i> <i>B</i> is 440 nm, and the wavelength range spans the full <i>E</i>+<i>S</i>+<i>C</i>+<i>L</i>+<i>U</i> band between 1,320 and 1,760 nm. The fault and manufacturing tolerance of the PBS was demonstrated for structural errors of ±1<i>%</i>. Moreover, the influence of temperature on the performance of the PBS was determined and discussed. Our results show that a PBS has excellent potential in optical fiber sensing and optical fiber communications.