Highly sensitive tuning of coupled optical ring resonators by microfluidics

  • Siyka I. Shopova
  • Yuze Sun
  • A. T. Rosenberger
  • Xudong Fan
Short Communication


The authors develop optofluidic coupled ring resonator (OCRR) system in which one of the ring resonators serves as a microfluidic channel. Highly sensitive tuning of the OCRR is demonstrated by making small changes in the refractive index of the fluid. A refractometric sensing scheme using the OCRR is proposed and demonstrated, allowing for measuring a refractive index change down to 10−9 refractive index units, two orders of magnitude better than a single ring resonator.


Coupled resonators Microfluidics Sensing 



The authors acknowledge the support from the Wallace Coulter Foundation Early Career Award and National Science Foundation-CAREER (CBET-0747398).


  1. Chao CY, Guo LJ (2003) Biochemical sensors based on polymer microrings with sharp asymmetrical resonance. Appl Phys Lett 83:1527–1529CrossRefGoogle Scholar
  2. Kurt H, Citrin DS (2005) Coupled-resonator optical waveguides for biochemical sensing of nanoliter volumes of analyte in the terahertz region. Appl Phys Lett 87:241119CrossRefGoogle Scholar
  3. Levy U, Campbell K, Groisman A, Mookherjea S, Fainman Y (2006) On-chip microfluidic tuning of an optical microring resonator. Appl Phys Lett 88:111107CrossRefGoogle Scholar
  4. Maleki L, Matsko AB, Savchenkov AA, Ilchenko VS (2004) Tunable delay line with interacting whispering-gallery-mode resonators. Opt Lett 29:626–628CrossRefGoogle Scholar
  5. Mario LY, Chin MK (2008) Optical buffer with higher delay-bandwidth product in a two-ring system. Opt Express 16:1796–1807CrossRefGoogle Scholar
  6. Naweed A, Farca G, Shopova SI, Rosenberger AT (2005) Induced transparency and absorption in coupled whispering-gallery microresonators. Phys Rev A 71:043804CrossRefGoogle Scholar
  7. Paloczi GT, Scheuer J, Yariv A (2005) Compact microring-based wavelength-selective inline optical reflector. IEEE Photonics Technol Lett 17:390–392CrossRefGoogle Scholar
  8. Passaro VMN, De Leonardis F (2006) Modeling and design of a novel high-sensitivity electric field silicon-on-insulator sensor based on a whispering-gallery-mode resonator. IEEE J Selected Top Quantum Electron 12:124–133CrossRefGoogle Scholar
  9. Psaltis D, Quake SR, Yang C (2006) Developing optofluidic technology through the fusion of microfluidics and optics. Nature 442:381–386CrossRefGoogle Scholar
  10. Sandhu S, Povinelli ML, Fan S (2007) Stopping and time reversing a light pulse using dynamic loss tuning of coupled-resonator delay lines. Opt Lett 32:3333–3335CrossRefGoogle Scholar
  11. Scheuer J, Yariv A (2006) Sagnac effect in coupled-resonator slow-light waveguide structures. Phys Rev Lett 96:053901CrossRefGoogle Scholar
  12. Scheuer J, Paloczi GT, Yariv A (2005) All optically tunable wavelength-selective reflector consisting of coupled polymeric microring resonators. Appl Phys Lett 87:251102CrossRefGoogle Scholar
  13. Smith DD, Chang H, Fuller KA (2003) Whispering-gallery mode splitting in coupled microresonators. J Opt Soc Am B Opt Phys 20:1967–1974CrossRefGoogle Scholar
  14. Suter JD, White IM, Zhu H, Fan X (2007) Thermal characterization of liquid core optical ring resonator sensors. Appl Opt 46:389–396CrossRefGoogle Scholar
  15. Totsuka K, Kobayashi N, Tomita M (2007) Slow light in coupled-resonator-induced transparency. Phys Rev Lett 98:213904CrossRefGoogle Scholar
  16. White IM, Oveys H, Fan X (2006) Liquid-core optical ring-resonator sensors. Opt Lett 31:1319–1321CrossRefGoogle Scholar
  17. Xiao YF, Gaddam V, Yang L (2008) Coupled optical microcavities: an enhanced refractometric sensing configuration. Opt Express 16:12538–12543CrossRefGoogle Scholar
  18. Xu Q, Shakya J, Lipson M (2006) Direct measurement of tunable optical delays on chip analogue to electromagnetically induced transparency. Opt Express 14:6463–6468CrossRefGoogle Scholar
  19. Xu Q, Dong P, Lipson M (2007) Breaking the delay-bandwidth limit in a photonic structure. Nat Phys 3:406–410CrossRefGoogle Scholar
  20. Yanik MF, Fan S (2007) Slow light—dynamic photon storage. Nat Phys 3:372–374CrossRefGoogle Scholar
  21. Yanik MF, Suh W, Wang Z, Fan SH (2004) Stopping light in a waveguide with an all-optical analog of electromagnetically induced transparency. Phys Rev Lett 93:233903CrossRefGoogle Scholar

Copyright information

© Springer-Verlag 2008

Authors and Affiliations

  • Siyka I. Shopova
    • 1
  • Yuze Sun
    • 1
  • A. T. Rosenberger
    • 2
  • Xudong Fan
    • 1
  1. 1.Biological Engineering DepartmentUniversity of MissouriColumbiaUSA
  2. 2.Department of PhysicsOklahoma State UniversityStillwaterUSA

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