Photonic Sensors

, Volume 9, Issue 1, pp 19–24 | Cite as

Highly Sensitive Refractive Index Sensor Based on Polymer Long-Period Waveguide Grating With Liquid Cladding

  • Lingfang WangEmail author
  • Keyu Ren
  • Bao Sun
  • Kaixin Chen
Open Access


We propose a novel structure and unique sensing mechanism bio-chemical sensor which is fabricated by a polymer long-period waveguide grating with the detection liquid directly as the waveguide cladding. Quantitative detection is realized from analyzing the output absorption spectrum and resonant wavelength shift related to the liquid detection concentration. The proposed polymer long-period waveguide grating based liquid refractive-index sensor is developed experimentally, the high sensitivity of 1.01 × 104 nm/RIU is achieved, and the temperature stability coefficient is 1.47 nm/°C. Theoretically and experimentally, this work has been demonstrated to have potential application in chemical and biological detections and may provide an important technical support for solving today’s increasingly serious civil problems such as food safety and drug safety, which will also have the important scientific significance and application prospects.


Optical sensor polymer waveguides long-period waveguide gratings liquid cladding 



This work was supported by the National Natural Science Foundation of China (NSFC) (Grant No. 61505020) and the Fundamental Research Funds for the Central Universities (Grant No. ZYGX2016J005).


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© The Author(s) 2018

Open Access This article is distributed under the terms of the Creative Commons Attribution 4.0 International License (, which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made.

Authors and Affiliations

  • Lingfang Wang
    • 1
    • 2
    Email author
  • Keyu Ren
    • 1
  • Bao Sun
    • 1
  • Kaixin Chen
    • 1
  1. 1.School of Electronic Science and EngineeringUniversity of Electronic Science and Technology of ChinaChengduChina
  2. 2.Hansen Experimental Physics Laboratory, Department of PhysicsStanford UniversityStanfordUSA

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