Abstract

Detecting explosive, flammable, or toxic industrial liquids reliably and accurately is a matter of civic responsibility that cannot be treated lightly. Tapered optical fibers (TOFs) and suspended core microstructured optical fibers (SC MOFs) were separately used as sensors of liquids without being compared to each other. We present a highly sensitive time-stable TOF sensor incorporated in the pipeline system for the in-line regime of measurement. This paper is furthermore focused on the comparison of this TOF and SC MOF of similar parameters for the detection of selected liquids. A validated method that incorporates TOF and SC MOF of small core (waist) diameter for refractometric detection is presented. The principle of detection is based on the overlap of an enhanced evanescent wave with a liquid analyte that either fills the cladding holes of the SC MOF or surrounds the waist area of the TOF. Optical power within the evanescent wave for both sensing structures and selected liquid analytes is analyzed. Measurement results concerning TOF and SC MOF are compared. Calculations to ascertain the limit of detection (LOD) for each sensor and the sensitivity ($S$) to refractive indices of liquid analytes in the range of 1.4269 to 1.4361 were performed at a wavelength of 1550 nm with the lowest refractive index step of 0.0007. Results affirming that $S=600.96\mathrm{dB}/\mathrm{RIU}$ and $LOD=0.0733\mathrm{RIU}$ for the SC MOF and $S=1143.2\mathrm{dB}/\mathrm{RIU}$ and LOD of 0.0026 RIU for the TOF sensor were achieved, clearly illustrating that TOF-based sensors can reach close to two times greater sensitivity and 30 times higher limit of detection. This paper extends the comparison of the fiber sensors by discussing the potential applications.

© 2017 Optical Society of America

Suspended-core microstructured fiber for refractometric detection of liquids

Tomas Nemecek, Matej Komanec, Tomas Martan, Redwan Ahmad, and Stanislav Zvanovec
Appl. Opt. 54(30) 8899-8903 (2015)

Fiber optic refractometric sensors using a semi-ellipsoidal sensing element

Amalia Nallely Castro Martinez, Matej Komanec, Tomas Nemecek, Stanislav Zvanovec, and Sergei Khotiaintsev
Appl. Opt. 55(10) 2574-2579 (2016)

Surface plasmon resonance chemical sensor composed of a microstructured optical fiber for the detection of an ultra-wide refractive index range and gas-liquid pollutants

Wei Liu, Ying Shi, Zao Yi, Chao Liu, Famei Wang, Xianli Li, Jingwei Lv, Lin Yang, and Paul K. Chu
Opt. Express 29(25) 40734-40747 (2021)

Optofluidic in-fiber interferometer based on hollow optical fiber with two cores

Tingting Yuan, Xinghua Yang, Zhihai Liu, Jun Yang, Song Li, Depeng Kong, Xiuxiu Qi, Wenting Yu, Qunlong Long, and Libo Yuan
Opt. Express 25(15) 18205-18215 (2017)

Opening up dual-core microstructured optical fiber-based plasmonic sensor with large detection range and linear sensitivity

Nannan Luan, Haixia Han, Lei Zhao, Jianfei Liu, and Jianquan Yao
Opt. Mater. Express 9(2) 819-825 (2019)