Title :
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
fDate :
7/1/2012 12:00:00 AM
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;
Journal_Title :
Sensors Journal, IEEE
DOI :
10.1109/JSEN.2012.2194700
