Optoelectronics Letters, Volume. 17, Issue 5, 271(2021)

Intermodal interference based refractive index sensor employing elliptical core photonic crystal fiber

Xu-jie WU1... Bin-bin SONG1,*, Ji-xuan WU2 and Wei HUANG1 |Show fewer author(s)
Author Affiliations
  • 1The 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
  • 2Tianjin Key Laboratory of Optoelectronic Detection Technology and Systems, College of Electronic and Information Engineering, Tiangong University, Tianjin 300387, China
  • show less

    A refractive index (RI) sensor based on elliptical core photonic crystal fiber (EC-PCF) has been proposed. The asymmetric elliptical core introduces the polarization-dependent characteristics of the fiber core modes. The performances of intermodal interference between the intrinsic polarization fiber core modes are investigated by contrast in two interferometers based on the Mach-Zehnder (M-Z) and Sagnac interference model. In addition, the RI sensing characteristics of the two interferometers are studied by successively filling the three layers air holes closest to the elliptical core in the cladding. The results show that the M-Z interference between LP01 and LP11 mode in the same polarized direction is featured with the incremental RI sensing sensitivity as the decreasing interference length, and the infilled scope around the elliptical core has a weak correlation with the RI sensing sensitivity. Due to the high birefringence of LP11 mode, the Sagnac interferometer has better RI sensing performance, the maximum RI sensing sensitivity of 12 000 nm/RIU is achieved under the innermost one layer air holes infilled with RI matching liquid of RI=1.39 at the pre-setting EC-PCF length of 12 cm, which is two orders of magnitude higher than the M-Z interferometer with the same fiber length. The series of theoretical optimized analysis would provide guidance for the applications in the field of biochemical sensing.

    Tools

    Get Citation

    Copy Citation Text

    WU Xu-jie, SONG Bin-bin, WU Ji-xuan, HUANG Wei. Intermodal interference based refractive index sensor employing elliptical core photonic crystal fiber[J]. Optoelectronics Letters, 2021, 17(5): 271

    Download Citation

    EndNote(RIS)BibTexPlain Text
    Save article for my favorites
    Paper Information

    Received: Nov. 5, 2020

    Accepted: Nov. 25, 2020

    Published Online: Sep. 2, 2021

    The Author Email: Bin-bin SONG (bbsong@email.tjut.edu.cn)

    DOI:10.1007/s11801-021-0175-6

    Topics