High-Sensitive Fiber-Optic Refractometer Based on a Core-Diameter-Mismatch Mach–Zehnder Interferometer

Author

Rong, Qiangzhou ; Qiao, Xueguang ; Wang, Ruohui ; Sun, Hao ; Hu, Manli ; Feng, Zhongyao

Author_Institution

Dept. of Phys., Northwest Univ., Xi´´an, China

Volume

12

Issue

7

fYear

2012

fDate

7/1/2012 12:00:00 AM

Firstpage

2501

Lastpage

2505

Abstract

An in-fiber Mach-Zehnder interferometer (MZI) for high-sensitive refractive index (RI) measurement is proposed and experimentally demonstrated. The sensing head is formed by a single-mode fiber (SMF) sandwiched between two short sections of thin-core fibers (TCFs), i.e., TCF-SMF-TCF MZI configuration with a length of 9 mm. A well-defined interference pattern is obtained as the result of fiber-core mismatch and core-cladding modes interference. The selected interference dip is extremely sensitive to ambient RI, providing a stable RI response with sensitivity up to 159 nm/RIU for water-based solutions close to the RI of 1.33, making it a good candidate for bio-chemical measurements.

Keywords

Mach-Zehnder interferometers; fibre optic sensors; light interference; optical fibres; refractive index; refractometers; TCF-SMF-TCF MZI configuration; biochemical measurement; core-cladding mode interference; core-diameter-mismatch Mach-Zehnder interferometer; fiber-core mismatch mode; high-sensitive fiber-optic refractometer; high-sensitive refractive index measurement; in-fiber Mach-Zehnder interferometer; interference pattern; selected interference dip; single-mode fiber; size 9 mm; stable RI response; water-based solution; Indexes; Interference; Interferometers; Optical fiber sensors; Optical fibers; Sensitivity; Fiber optics; fiber optics sensors;

fLanguage

English

Journal_Title

Sensors Journal, IEEE

Publisher

ieee

ISSN

1530-437X

Type

jour

DOI

10.1109/JSEN.2012.2194700

Filename

6183456