A Review of Sensitivity Enhancement in Interferometer-Based Fiber Sensors
Zengrun Wen,
Ziqing Guan,
Jingru Dong,
Hongxin Li,
Yangjian Cai,
Song Gao
Affiliations
Zengrun Wen
Center of Light Manipulations and Applications & Shandong Provincial Key Laboratory of Optics and Photonic Device, School of Physics and Electronics, Shandong Normal University, Jinan 250014, China
Ziqing Guan
School of Physics and Electronics, Shandong Normal University, Jinan 250014, China
Jingru Dong
School of Physics and Electronics, Shandong Normal University, Jinan 250014, China
Hongxin Li
School of Physics and Electronics, Shandong Normal University, Jinan 250014, China
Yangjian Cai
Center of Light Manipulations and Applications & Shandong Provincial Key Laboratory of Optics and Photonic Device, School of Physics and Electronics, Shandong Normal University, Jinan 250014, China
Song Gao
Center of Light Manipulations and Applications & Shandong Provincial Key Laboratory of Optics and Photonic Device, School of Physics and Electronics, Shandong Normal University, Jinan 250014, China
Optical fiber sensors based on an interferometer structure play a significant role in monitoring physical, chemical, and biological parameters in natural environments. However, sensors with high-sensitivity measurement still present their own challenges. This paper deduces and summarizes the methods of sensitivity enhancement in interferometer based fiber optical sensors, including the derivation of the sensing principles, key characteristics, and recently-reported applications.The modal coupling interferometer is taken as an example to derive the five terms related to the sensitivity: (1) the wavelength-dependent difference of phase between two modes/arms ∂ϕd/∂λ, (2) the sensor length Lw,A, (3) refractive index difference between two modes/arms Δneff,A, (4) sensing parameter dependent length change α, and (5) sensing parameter dependent refractive index change γ. The research papers in the literature that modulate these terms to enhance the sensing sensitivity are reviewed in the paper.
