Au-Nanocoated Twisted-SMF for Multiparameter Sensor

Abstract In this paper, we experimentally demonstrated the application of the Au-nanocoated twisted single-mode fiber (Au-TSMF) structure for the response of the multiparameter. Firstly, we fabricated an Au-TSMF, which achieved high sensitivity to refractive index (RI) and torsion. Additionally, based on the theory of polarization interference, we amplified its polarization sensitivity and induced the phase factor caused by polarization as a wavelength shift. Ultimately, we achieved the response of the Au-TSMF structure to the multiparameter, which had the sensitivity of −0.436 dB/(deg/m) for clockwise torsion, −0.156 dB/(deg/m) for anticlockwise torsion, 0.391 5 nm/rad for the left-handed circularly polarized state, −0.926 nm/rad for the right-handed circularly polarized state, and −692.9 dB/RIU for RI. Due to the advantages of the all-fiber integrated system, this work holds great potential for facilitating fiber optic integrated devices for optical fiber biosensors and biomedical diagnostic applications.