Photonic Sensors

, Volume 7, Issue 2, pp 97–104 | Cite as

Optofluidic refractive index sensor based on partial reflection

  • Lei Zhang
  • Zhang Zhang
  • Yichuan Wang
  • Meiying Ye
  • Wei Fang
  • Limin Tong
Open Access


We demonstrate a novel optofluidic refractive index (RI) sensor with high sensitivity and wide dynamic range based on partial reflection. Benefited from the divergent incident light and the output fibers with different tilting angles, we have achieved highly sensitive RI sensing in a wide range from 1.33 to 1.37. To investigate the effectiveness of this sensor, we perform a measurement of RI with a resolution of ca. 5.0×10–5 refractive index unit (RIU) for ethylene glycol solutions. Also, we have measured a series of liquid solutions by using different output fibers, achieving a resolution of ca. 0.52 mg/mL for cane surge. The optofluidic RI sensor takes advantage of the high sensitivity, wide dynamic range, small footprint, and low sample consumption, as well as the efficient fluidic sample delivery, making it useful for applications in the food industry.


Optofluidic sensor refractive index partial reflection 



This work has been supported in part by National Basic Research Program of China (Nos. 2013CB328703 and 2014CB921303), and National Natural Science Foundation of China (61275217, 21407039).


  1. [1]
    D. Psaltis, S. R. Quake, and C. H. Yang, “Insight review: developing optofluidic technology through the fusion of microfluidics and optics,” Nature, 2006, 442(7101): 381–386.ADSCrossRefGoogle Scholar
  2. [2]
    C. Monat, P. Domachuk, and B. J. Eggleton, “Integrated optofluidics: a new river of light,” Nature Photonics, 2007, 1(2): 106–114.ADSCrossRefGoogle Scholar
  3. [3]
    D. B. Wolfe, R. S. Conroy, P. Garstecki, B. T. Mayers, M. A. Fischbach, K. E. Paul, et al., “Dynamic control of liquid-core/liquid-cladding optical waveguides,” Proceedings of the National Academy of Sciences, 2004, 101(34): 12434–12438.ADSCrossRefGoogle Scholar
  4. [4]
    B. T. Mayers, D. V. Vezenov, V. I. Vullev, and G. M. Whitesides, “Arrays and cascades of fluorescent liquid-liquid waveguides: broadband light sources for spectroscopy in microchannels,” Analytical Chemistry, 2005, 77(5): 1310–1316.CrossRefGoogle Scholar
  5. [5]
    X. L. Mao, J. R. Waldeisen, B. K. Juluri, and T. J. Huang, “Hydrodynamically tunable optofluidic cylindrical microlens,” Lab on a Chip, 2007, 7(10): 1303–1308.CrossRefGoogle Scholar
  6. [6]
    P. Fei, Z. He, C. Zheng, T. Chen, Y. Men, and Y. Huang, “Discretely tunable optofluidic compound microlenses,” Lab on a Chip, 2011, 11(17): 2835–2841.CrossRefGoogle Scholar
  7. [7]
    A. Groisman, S. Zamek, K. Campbell, L. Pang, U. Levy, and Y. Fainman, “Optofluidic 1×4 switch,” Optics Express, 2008, 16(18): 13499–13508.ADSCrossRefGoogle Scholar
  8. [8]
    W. Z. Song and D. Psaltis, “Electrically tunable optofluidic light switch for reconfigurable solar lighting,” Lab on a Chip, 2013, 13(14): 2708–2713.CrossRefGoogle Scholar
  9. [9]
    Y. Hongbin, Z. Guangya, C. F. Siong, and L. Feiwen, “Optofluidic variable aperture,” Optics Letters, 2008, 33(6): 548–550.ADSCrossRefGoogle Scholar
  10. [10]
    C. L. Song, N. T. Nguyen, A. K. Asundi, and C. L. N. Low, “Tunable optofluidic aperture configured by a liquid-core/liquid-cladding structure,” Optics Letters, 2011, 36(10): 1767–1769.ADSCrossRefGoogle Scholar
  11. [11]
    Z. Li, Z. Zhang, T. Emery, A. Scherer, and D. Psaltis, “Single mode optofluidic distributed feedback dye laser,” Optics Express, 2006, 14(2): 696–701.ADSCrossRefGoogle Scholar
  12. [12]
    M. Aas, A. Jonas, A. Kiraz, O. Brzobohaty, J. Jezek, Z. Pilat, and P. Zemanek, “Spectral tuning of lasing emission from optofluidic droplet microlasers using optical stretching,” Optics Express, 2013, 21(18): 21380–21394.ADSCrossRefGoogle Scholar
  13. [13]
    C. Grillet, P. Domachuk, V. Ta'eed, E. Mägi, J. Bolger, B. Eggleton, et al., “Compact tunable microfluidic interferometer,” Optics Express, 2004, 12(22): 5440–5447.ADSCrossRefGoogle Scholar
  14. [14]
    Y. Zou, Z. Hen, X. Hen, Z. Di, and X. Chen, “An integrated tunable interferometer controlled by liquid diffusion in polydimethylsiloxane,” Optics Express, 2012, 20(17): 18931–18936.ADSCrossRefGoogle Scholar
  15. [15]
    M. Hashimoto, B. Mayers, P. Garstecki, and G. M. Whitesides, “Flowing lattices of bubbles as tunable, self-assembled diffraction gratings,” Small, 2006, 2(11): 1292–1298.CrossRefGoogle Scholar
  16. [16]
    J. Q. Yu, Y. Yang, A. Q. Liu, L. K. Chin, and X. M. Zhang, “Microfluidic droplet grating for reconfigurable optical diffraction,” Optics Letters, 2010, 35(11): 1890–1892.ADSCrossRefGoogle Scholar
  17. [17]
    P. Liu, H. Huang, T. Cao, X. Liu, Z. Qi, Z. Tang, et al., “An ultra-low detection-limit optofluidic biosensor with integrated dual-channel Fabry-Pérot cavity,” Applied Physics Letters, 2013, 102(16): 163701-1–163701-4.ADSCrossRefGoogle Scholar
  18. [18]
    A. A. P. Trichet, J. Foster, N. E. Omori, D. James, P. R. Dolan, G. M. Hughes, et al., “Open-access optical microcavities for lab-on-a-chip refractive index sensing,” Lab on a Chip, 2014, 14(21): 4244–4249.CrossRefGoogle Scholar
  19. [19]
    Z. Xu, K. Han, I. Khan, X. Wang, and G. L. Liu, “Liquid refractive index sensing independent of opacity using an optofluidic diffraction sensor,” Optics Letters, 2014, 39(20): 6082–6085.ADSCrossRefGoogle Scholar
  20. [20]
    C. Wu, M. L. V. Tse, Z. Liu, B. O. Guan, A. P. Zhang, C. Lu, et al., “In-line microfluidic integration of photonic crystal fibers as a highly sensitive refractometer,” Analyst, 2014, 139(21): 5422–5429.ADSCrossRefGoogle Scholar
  21. [21]
    X. D. Fan and I. M. White, “Optofluidic microsystems for chemical and biological analysis,” Nature Photonics, 2011, 5(10): 591–297.ADSCrossRefGoogle Scholar
  22. [22]
    D. Erickson, D. Sinton, and D. Psaltis, “Optofluidics for energy applications,” Nature Photonics, 2011, 5(10): 583–590.ADSCrossRefGoogle Scholar
  23. [23]
    L. Pang, H. M. Chen, L. M. Freeman, and Y. Fainman, “Optofluidic devices and applications in photonics, sensing and imaging,” Lab on a Chip, 2012, 12(19): 3543–3551.CrossRefGoogle Scholar
  24. [24]
    P. J. Viskari and J. P. Landers, “Unconventional detection methods for microfluidic devices,” Electrophoresis, 2006, 27(9): 1797–1810.CrossRefGoogle Scholar
  25. [25]
    Y. Wang, S. Meng, Y. Liang, L. Li, and W. Peng, “Fiber-optic surface plasmon resonance sensor with multi-alternating metal layers for biological measurement,” Photonic Sensors, 2013, 3(3): 202–207.ADSCrossRefGoogle Scholar
  26. [26]
    J. Zhu, L. Qin, S. Song, J. Zhong, and S. Lin, “Design of a surface plasmon resonance sensor based on grating connection,” Photonic Sensors, 2015, 5(2): 159–165.ADSCrossRefGoogle Scholar
  27. [27]
    L. K. Chin, A. Q. Liu, Y. C. Soh, C. S. Lim, and C. L. Lin, “A reconfigurable optofluidic Michelson interferometer using tunable droplet grating,” Lab on a Chip, 2010, 10(8): 1072–1078.CrossRefGoogle Scholar
  28. [28]
    M. I. Lapsley, I. K. Chiang, Y. B. Zheng, X. Y. Ding, X. L. Mao, and T. J. Huang, “A single-layer, planar, optofluidic Mach-Zehnder interferometer for label-free detection,” Lab on a Chip, 2011, 11(10): 1795–1800.CrossRefGoogle Scholar
  29. [29]
    W. Z. Song, X. M. Zhang, A. Q. Liu, C. S. Lim, P. H. Yap, and H. M. M. Hosseini, “Refractive index measurement of single living cells using on-chip Fabry-Pérot cavity,” Applied Physics Letters, 2006, 89(20): 203901-1–203901-3.ADSCrossRefGoogle Scholar
  30. [30]
    Y. Guo, H. Li, K. Reddy, H. S. Shelar, V. R. Nittoor, and X. Fan, “Optofluidic Fabry-Pérot cavity biosensor with integrated flow-through micro-/ nanochannels,” Applied Physics Letters, 2011, 98(4): 041104-1–041104-3.ADSCrossRefGoogle Scholar
  31. [31]
    L. Q. Ren, X. Wu, M. Li, X. W. Zhang, L. Y. Liu, and L. Xu, “Ultrasensitive label-free coupled optofluidic ring laser sensor,” Optics Letters, 2012, 37(18): 3873–3875.ADSCrossRefGoogle Scholar
  32. [32]
    M. Li, X. Wu, L. Y. Liu, X. D. Fan, and L. Xu, “Self-Referencing optofluidic ring resonator sensor for highly sensitive biomolecular detection,” Analytical Chemistry, 2013, 85(19): 9328–9332.CrossRefGoogle Scholar
  33. [33]
    W. Liang, Y. Y. Huang, Y. Xu, R. K. Lee, and A. Yariv, “Highly sensitive fiber Bragg grating refractive index sensors,” Applied Physics Letters, 2005, 86(15): 151122-1–151122-3.ADSCrossRefGoogle Scholar
  34. [34]
    F. Xu, G. Brambilla, and Y. Q. Lu, “A microfluidic refractometric sensor based on gratings in optical fibre microwires,” Optics Express, 2009, 17(23): 20866–20871.ADSCrossRefGoogle Scholar
  35. [35]
    J. Wu, D. Day, and M. Gu, “A microfluidic refractive index sensor based on an integrated threedimensional photonic crystal,” Applied Physics Letters, 2008, 92(7): 071108-1–071107-3.ADSCrossRefGoogle Scholar
  36. [36]
    A. P. Zhang, G. Yan, S. Gao, S. He, B. Kim, J. Im, et al., “Microfluidic refractive-index sensors based on small-hole microstructured optical fiber Bragg gratings,” Applied Physics Letters, 2011, 98(22): 221109-1–221109-3.ADSCrossRefGoogle Scholar
  37. [37]
    Y. Wang, S. Meng, Y. Liang, L. Li, and W. Peng, “Fiber-optic surface plasmon resonance sensor with multi-alternating metal layers for biological measurement,” Photonic Sensors, 2013, 3(3): 202–207.ADSCrossRefGoogle Scholar
  38. [38]
    J. Zhu, L. Qin, S. Song, J. Zhong, and S. Lin, “Design of a surface plasmon resonance sensor based on grating connection,” Photonic Sensors, 2015, 5(2): 159–165.ADSCrossRefGoogle Scholar
  39. [39]
    T. J. Huang, M. I. Lapsley, S. C. S. Lin, and X. L. Mao, “An in-plane, variable optical attenuator using a fluid-based tunable reflective interface,” Applied Physics Letters, 2009, 95(8): 083507-1–083507-3.ADSCrossRefGoogle Scholar
  40. [40]
    E. Weber and M. J. Vellekoop, “Optofluidic micro-sensors for the determination of liquid concentrations,” Lab on a Chip, 2012, 12(19): 3754–3759.CrossRefGoogle Scholar
  41. [41]
    D. Qin, Y. Xia, and G. M. Whitesides, “Soft lithography for micro- and nanoscale patterning,” Nature Protocols, 2010, 5(3): 491–502.CrossRefGoogle Scholar

Copyright information

© The Author(s) 2017

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

  1. 1.State Key Laboratory of Modern Optical Instrumentation, College of Optical Science and EngineeringZhejiang UniversityHangzhouChina
  2. 2.College of Material, Chemistry and Chemical EngineeringHangzhou Normal UniversityHangzhouChina

Personalised recommendations