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Virtual Journal for Biomedical Optics

Virtual Journal for Biomedical Optics


  • Editors: Andrew Dunn and Anthony Durkin
  • Vol. 6, Iss. 9 — Oct. 3, 2011

Highly sensitive refractive index sensor based on two cascaded special long-period fiber gratings with rotary refractive index modulation

Yan-en Fan, Tao Zhu, Leilei Shi, and Yun-Jiang Rao  »View Author Affiliations

Applied Optics, Vol. 50, Issue 23, pp. 4604-4610 (2011)

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We present a refractive index (RI) sensor based on a fiber Mach–Zehnder interferometer (MZI) formed by two cascaded special long-period fiber gratings (LPFGs) with rotary refractive index modulation (RLPFGs), in which the coupling occurred between the guided mode and the high-order asymmetric cladding mode. The experimental results show that the RI sensitivity of a refractometer with an interaction length of 40 mm is up to 58.8 nm / RI in the range of 1.3344 to 1.3637, which is 3.5 times higher than that of an MZI formed by two normal LPFGs. The temperature sensitivity for the same parameters of an RLPFG-MZI is about 0.03 nm / ° C . Such a kind of high-sensitivity, easy-to-fabricate and simple-structure interferometer may find applications in the chemical or biochemical sensing fields.

© 2011 Optical Society of America

OCIS Codes
(030.4070) Coherence and statistical optics : Modes
(050.2770) Diffraction and gratings : Gratings
(060.2370) Fiber optics and optical communications : Fiber optics sensors
(120.3180) Instrumentation, measurement, and metrology : Interferometry
(280.5715) Remote sensing and sensors : Refractivity profiles

ToC Category:
Fiber Optics and Optical Communications

Original Manuscript: March 1, 2011
Revised Manuscript: May 6, 2011
Manuscript Accepted: June 21, 2011
Published: August 3, 2011

Virtual Issues
Vol. 6, Iss. 9 Virtual Journal for Biomedical Optics

Yan-en Fan, Tao Zhu, Leilei Shi, and Yun-Jiang Rao, "Highly sensitive refractive index sensor based on two cascaded special long-period fiber gratings with rotary refractive index modulation," Appl. Opt. 50, 4604-4610 (2011)

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