Multifunctional in-fiber polarization beam splitter using liquid crystal infiltrated dual-core photonic crystal fiber with gold layers and its temperature sensing characteristic

This work presents a compact polarization beam splitter using liquid crystal infiltrated dual-core photonic crystal fiber with gold layers. The finite element tool is utilized to analyze the in-fiber coupling characteristics, aiming to investigate the beam splitting performance and sensing capabilities. Simulation results indicate that when the appropriate structural parameters are determined, the coupling length ratio at 1.55 μm is approximately equal to 2 and the minimum length of 14.43 μm can be achieved. Both cores exhibit excellent beam splitting performance. In core A, the maximum extinction ratio of 89.04 dB is achieved with a bandwidth of 180 nm covering the S, C, and L bands. In core B, the maximum extinction ratio of 80.03 dB is achieved with a bandwidth of 240 nm fully covering the S, C, L, and U bands. Simultaneously, as a temperature sensor, it has a sensitivity of 2.1 nm/℃ and a high linearity of 0.99573. Additionally, with the use of the existing process, this splitter can be manufactured. There are reasons to believe that this multifunctional all-fiber device is anticipated to be one of key components in photonic integration, all-optical networks, and distributed sensing.