Refractive index sensitivity characteristics near the dispersion turning point of the multimode microfiber-based Mach–Zehnder interferometer


The turning point of the refractive index (RI) sensitivity based on the multimode microfiber (MMMF) in-line Mach–Zehnder interferometer (MZI) is observed. By tracking the resonant wavelength shift of the MZI generated between the HE11 and HE12 modes in the MMMF, the surrounding RI (SRI) could be detected. Theoretical analysis demonstrates that the RI sensitivity will reach ±∞ on either side of the turning point due to the group effective RI difference (퐺) approaching zero. Significantly, the positive sensitivity exists in a very wide fiber diameter range, while the negative sensitivity can be achieved in a narrow diameter range of only 0.3 μm. Meanwhile, the experimental sensitivities and variation trend at different diameters exhibit high consistency with the theoretical results. High RI sensitivity of 10777.8 nm/RIU (RI unit) at the fiber diameter of 4.6 μm and the RI around 1.3334 is realized. The discovery of the sensitivity turning points has great significance on trace detection due to the possibility of ultrahigh RI sensitivity.

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Divisions: College of Engineering & Physical Sciences > Aston Institute of Photonics Technology (AIPT)
Additional Information: © 2015 Optical Society of America. One print or electronic copy may be made for personal use only. Systematic reproduction and distribution, duplication of any material in this paper for a fee or for commercial purposes, or modifications of the content of this paper are prohibited. Funding: National Natural Science Foundation of China (61275004); Sub‐Project of the Major Program of the National Natural Science Foundation of China (61290315); European Commission's Marie Curie International Incoming fellowship (328263); Natural Science Foundation of Hubei Province for Distinguished Young Scholars (2014CFA036).
Publication ISSN: 1539-4794
Last Modified: 16 Apr 2024 07:11
Date Deposited: 26 Jan 2016 14:20
Full Text Link: https://www.osa ... I=ol-40-21-5042
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PURE Output Type: Article
Published Date: 2015-11-01
Accepted Date: 2015-10-04
Submitted Date: 2015-10-01
Authors: Luo, Haipeng
Sun, Qizhen
Li, Xiaolei
Yan, Zhijun
Li, Yanpeng
Liu, Deming
Zhang, Lin (ORCID Profile 0000-0002-1691-5577)



Version: Accepted Version

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