Vernier effect assisted sucrose sensor based on a cascaded Sagnac interferometer with no-core fiber

Yuanfang Zhao; Manthangal Sivanesan Aruna Gandhi; Qian Li; Zhengyong Liu; H Y Fu

doi:10.1364/BOE.444620

Vernier effect assisted sucrose sensor based on a cascaded Sagnac interferometer with no-core fiber

Biomed Opt Express. 2021 Nov 8;12(12):7338-7347. doi: 10.1364/BOE.444620. eCollection 2021 Dec 1.

Authors

Yuanfang Zhao¹, Manthangal Sivanesan Aruna Gandhi², Qian Li², Zhengyong Liu^{3

4}, H Y Fu¹

Affiliations

¹ Tsinghua Shenzhen International Graduate School & Tsinghua-Berkeley Shenzhen Institute (TBSI), Tsinghua University, Shenzhen 518055, China.
² School of Electronics and Computer Engineering, Peking University, Shenzhen 518055, China.
³ Guangdong Provincial Key Laboratory of Optoelectronic Information Processing Chips and Systems, School of Electronics and Information Technology, Sun Yat-sen University, Guangzhou 510275, China.
⁴ Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), Zhuhai 519000, China.

Abstract

We propose a sucrose concentration sensor by utilizing a fiber Sagnac interferometer with no-core fiber (SI-NCF) based on the Vernier effect. The Vernier effect is realized by introducing a single Sagnac interferometer (SI) with a similar free spectral range of SI-NCF. When the NCF is exposed to the external sucrose solution, the cladding state of NCF is changed, which induces the wavelength shift of the SI-NCF. The measured sucrose concentration sensitivity of a single SI-NCF is 2.97 nm/M, and the sensitivity can be improved to -13.84 nm/M with the assistance of the Vernier effect, which is 4.66 times of the single SI-NCF. The sensor has the advantages of high sensitivity, easy-fabrication and cost-effectiveness which can be applied in the field of the food industry, chemistry and agriculture.