Review of no-core optical fiber sensor and applications

• Published in: Sensors and actuators. A. Physical. Vol. 313; p. 112160
• Main Authors: Zhao, Yong, Zhao, Jian, Zhao, Qiang
• Format: Journal Article
• Language: English
• Published: Lausanne Elsevier B.V 01.10.2020; Elsevier BV
• Subjects: Biosensors; Evanescent waves; Fiber optics; Gratings (spectra); Measurement; Measurement methods; Multimode interference; No-core fiber; Optical fibers; Parameter sensitivity; Remote sensing; Self-imaging; Sensing applications; Sensing structures; Sensors; Studies; Waveguides; No-core fiber; Self-imaging; Multimode interference; Sensing applications; Sensing structures
• ISSN: 0924-4247; 1873-3069
• DOI: 10.1016/j.sna.2020.112160

The structural diagram (a) and transmission respond (b) of MNM structure sensor [34]. The schematic diagram of MNM structure and transmission respond of surrounding RI are shown in Fig. 1. The resonant wavelength shifts to long-wavelength direction and relative transmitted power changes simultaneously while increasing surrounding RI from 1.3 to 1.42. And then, Y. Li et al further achieved the measurement relative error of 0.1 % merely by slightly reducing the NCF diameter [35].This kind of MNM structure has the advantages of high reliability and preferable practicability due to the simple fusion fabrication process. [Display omitted] The unique structural characteristic of no-core fiber (NCF) have extended the sensing applications based on multimode interference self-imaging, evanescent wave absorption and materials coating, which are widely used in the measurement of various physical, chemical and biological parameters. An overview of the NCF-based sensing applications is spread out with specific emphasis on measurement methods, structural improvements and the combination of sensitive materials. Different prototypes of NCF-based sensors are meticulously outlined. First, the single NCF-based sensors with different analysis principles are reviewed, and the advantages of structural improvement including fiber taper, lateral-offset fusing and internal waveguide writing are compared. Second, the cascading of NCF with fiber gratings or other structures to realize multi-parameter measurement and widen the application field are also discussed. Then, NCF combines sensitive materials to measure physical/chemical parameters or coats metal film to excite surface plasmon resonance are addressed, and representative examples of the latest research progress are presented to confirm the potential value of NCF-based sensors in biosensing. What’s more, the sensing characteristics of applying NCF structure in different ways are also introduced. In a whole, this article detailedly summarizes the sensing applications, concludes the challenges and points out the research direction in the development of NCF-based sensors.