Dual-demodulation large-scope high-sensitivity refractive index sensor based on twin-core PCF

Chen-Yuan Li; Bin-Bin Song; Ji-Xuan Wu; Wei Huang; Xu-Jie Wu; Chang Jin

doi:10.1007/s11801-021-0129-z

Dual-demodulation large-scope high-sensitivity refractive index sensor based on twin-core PCF

Optoelectron Lett. 2021;17(4):193-198. doi: 10.1007/s11801-021-0129-z. Epub 2021 Apr 14.

Authors

Chen-Yuan Li¹, Bin-Bin Song¹, Ji-Xuan Wu², Wei Huang¹, Xu-Jie Wu¹, Chang Jin¹

Affiliations

¹ The Key Laboratory of Computer Vision and System of Ministry of Education, Tianjin Key Laboratory of Intelligence Computing and Novel Software Technology, Tianjin University of Technology, Tianjin, 300384 China.
² Tianjin Key Laboratory of Optoelectronic Detection Technology and Systems, College of Electronic and Information Engineering, Tiangong University, Tianjin, 300387 China.

Abstract

In this paper, a refractive index (RI) sensor based on the twin-core photonic crystal fiber (TC-PCF) is presented. Introducing the rectangular array in the core area makes the PCF possible to obtain high birefringence and low confinement loss over the wavelength range from 0.6 µm to 1.7 µm. Therefore, the core region can enhance the interaction between the core mode and the filling material. We studied theoretically the evolution characteristics of the birefringence and operating wavelength corresponding to the strongest polarization point under the condition of filling the rectangular array with RI matching fluid range from 1.33 to 1.41. Simulation results reveal that the proposed TC-PCF has opposite evolutions of change rates between the B and wavelength, and the maximum RI sensing sensitivities of 1.809×10^-2 B/RIU and 8 700 nm/RIU at low and high RI infill are obtained respectively, which means that the TC-PCF features of dual-parameter demodulation for the RI sensing can maintain a high refractive index sensing sensitivity within a large scope of RI ranging from 1.33 to 1.41. Compared with the results of single-parameter demodulation, it is an optimized method to improve the sensitivity of low refractive index sensors, which has great application potency in the field of biochemical sensing and detection.