Novel fiber optic distributed refractive index sensing method by optical frequency domain reflectometry

Zongda Zhu; Yongkang Dong

doi:10.1117/12.2625075

27 March 2022 Novel fiber optic distributed refractive index sensing method by optical frequency domain reflectometry

Zongda Zhu, Yongkang Dong

Proceedings Volume 12169, Eighth Symposium on Novel Photoelectronic Detection Technology and Applications; 121697W (2022) https://doi.org/10.1117/12.2625075
Event: Eighth Symposium on Novel Photoelectronic Detection Technology and Applications, 2021, Kunming, China

Abstract

We proposed a novel fiber-optic distributed refractive index (RI) sensing method by optical frequency domain reflectometry (OFDR), which is qualified for most scenes such as solution diffusion process and multi-analytes detection that require distributed RI sensing ability. We use a section of multi-core fiber (MCF) as the sensing fiber, which consists of one central core and six outer surrounding cores. The MCF is etched by hydrofluoric acid until the outer cores are exposed to the air, thus the effective index of outer cores will be affected by the RI of the surrounding samples, which will lead the wavelength shift of the Rayleigh backscattering (RBS) spectrum. In order to realize distributed RI sensing, we introduce the OFDR technique, which has excellent ability of spatial localization. Then, by demodulating the wavelength shift of the local RBS spectrum, the distributed RI sensing is realized. The sensing length of 19 cm and the spatial resolution of 5.3 mm are achieved in experiment. The RI sensing range is as wide as 1.33~1.44 RIU, and the maximum sensitivity of 47 nm/RIU is obtained around 1.44 RIU. In addition, the central core can be used for temperature compensation because it keeps isolated to the surrounding sample. The experimental results indicate that the temperature sensitivity reaches 9.8 pm/°C during 25~80°C. By temperature compensation, the RI measurement error induced by temperature disturbance can be eliminated. Finally, we successfully detect the diffusion process of glycerol in water using the proposed fiber-optic distributed RI sensor.

Citation Download Citation

Zongda Zhu and Yongkang Dong "Novel fiber optic distributed refractive index sensing method by optical frequency domain reflectometry", Proc. SPIE 12169, Eighth Symposium on Novel Photoelectronic Detection Technology and Applications, 121697W (27 March 2022); https://doi.org/10.1117/12.2625075

ACCESS THE FULL ARTICLE

INSTITUTIONAL
Select your institution to access the SPIE Digital Library.

SELECT YOUR INSTITUTION

PERSONAL
Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.

PERSONAL SIGN IN

No SPIE Account? Create one

PURCHASE THIS CONTENT

SUBSCRIBE TO DIGITAL LIBRARY

50 downloads per 1-year subscription

Members: $195

Non-members: $335 ADD TO CART

25 downloads per 1 - year subscription

Members: $145

Non-members: $250 ADD TO CART

PURCHASE SINGLE ARTICLE

Includes PDF, HTML & Video, when available

Members: $17.00

Non-members: $21.00 ADD TO CART

PROCEEDINGS
5 PAGES

DOWNLOAD PAPER SAVE TO MY LIBRARY

GET CITATION

RIGHTS & PERMISSIONS

Get copyright permission Get copyright permission on Copyright Marketplace

KEYWORDS

Fiber optics sensors

Fiber optics

Sensing systems

Temperature metrology

Backscatter

Interferometers

Refractive index

Show All Keywords

Keywords/Phrases

Search In:

Publication Years