Ultra-short polarization beam splitter with square lattice and gold film based on dual-core photonic crystal fiber

摘要

An octagonal photonic crystal fiber polarization beam splitter with gold-plated film is proposed. The polarization beam splitter characteristics are studied by optimizing the gold film thickness, the cladding air hole diameter and the air hole spacing. At the communication wavelength of 1.55 mu m, the coupling ratio can reach the ideal value of 2. Under the optimum geometric parameters, the curve of the coupling length with the working wavelength is flat. When the gold film thickness, cladding air hole diameter and air hole spacing are 15 nm, 1.228 mu m and 1.5 mu m respectively, the beam splitting length and extinction ratio of the polarization beam splitter are 47.26 mu m and -151.43 dB respectively. Because the polarization beam splitter has extremely short beam splitting length and high extinction ratio, it has great value in the field of large-capacity integrated optics and optical communication systems.