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Optics Express

Optics Express

  • Editor: Andrew M. Weiner
  • Vol. 21, Iss. 19 — Sep. 23, 2013
  • pp: 22817–22828

Towards more accurate microcavity sensors: maximum likelihood estimation applied to a combination of quality factor and wavelength shifts

M. Imran Cheema, Usman A. Khan, Andrea M. Armani, and Andrew G. Kirk  »View Author Affiliations

Optics Express, Vol. 21, Issue 19, pp. 22817-22828 (2013)

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Optical microcavities are widely used for biological and chemical sensing applications. In these devices, a sensing event is estimated by measuring the shift in the resonant wavelength, or in the quality factor of the microcavity. However, all published works to date only use one of these measures to estimate the sensing event. Here, we show that the estimation accuracy of a sensing event can be improved by employing a combination of both the quality factor and the resonant wavelength measurements in a microcavity sensor. We further demonstrate an experimental application of this model by introducing a refractive index change for a microtoroidal cavity sensor immersed in a liquid. By further using the finite element method simulations in conjunction with the estimator model, we show the existence of three distinct measurement regimes as a function of the quality factor of the microcavity. Finally, the estimator model is extended to develop a sensing metric to compare performance of optical or non-optical sensors.

© 2013 OSA

OCIS Codes
(280.1415) Remote sensing and sensors : Biological sensing and sensors
(280.1545) Remote sensing and sensors : Chemical analysis
(140.3945) Lasers and laser optics : Microcavities
(140.3948) Lasers and laser optics : Microcavity devices
(280.4788) Remote sensing and sensors : Optical sensing and sensors

ToC Category:

Original Manuscript: June 26, 2013
Revised Manuscript: August 30, 2013
Manuscript Accepted: August 31, 2013
Published: September 20, 2013

M. Imran Cheema, Usman A. Khan, Andrea M. Armani, and Andrew G. Kirk, "Towards more accurate microcavity sensors: maximum likelihood estimation applied to a combination of quality factor and wavelength shifts," Opt. Express 21, 22817-22828 (2013)

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  1. H. K. Hunt and A. M. Armani, “Label-free biological and chemical sensors,” Nanoscale2, 1544–1559 (2010). [CrossRef] [PubMed]
  2. F. Vollmer and L. Yang, “Label-free detection with high-Q microcavities: a review of biosensing mechanisms for integrated devices,” Nanophotonics267–291 (2012).
  3. L. Maleki and V. S. Ilchenko, “Techniques and devices for sensing a sample by using a whispering gallery mode resonator,” US Patent6490039 (2002).
  4. J. L. Nadeau, V. S. Ilchenko, D. Kossakovski, G. H. Bearman, and L. Maleki, “High-Q whispering-gallery mode sensor in liquids,” Proc. SPIE4629, 172–180 (2002). [CrossRef]
  5. A. M. Armani and K. J. Vahala, “Heavy water detection using ultra-high-Q microcavities,” Opt. Lett.31, 1896–1898 (2006). [CrossRef] [PubMed]
  6. D. K. Armani, T. J. Kippenberg, S. M. Spillane, and K. J. Vahala, “Ultra-high-Q toroid microcavity on a chip,” Nature421(2003). [CrossRef] [PubMed]
  7. J. Barnes, B. Carver, J. M. Fraser, G. Gagliardi, H. P. Loock, Z. Tian, M. W. B. Wilson, S. Yam, and O. Yastrubshak, “Loss determination in microsphere resonators by phase-shift cavity ring-down measurements,” Opt. Express16, 13158–13167 (2008). [CrossRef] [PubMed]
  8. M. I. Cheema, S. Mehrabani, A. A. Hayat, Y.-A. Peter, A. M. Armani, and A. G. Kirk, “Simultaneous measurement of quality factor and wavelength shift by phase shift microcavity ring down spectroscopy,” Opt. Express20, 9090–9098 (2012). [CrossRef] [PubMed]
  9. L. L. Scharf, Statistical Signal Processing: Detection, Estimation, and Time Series Analysis (Addison-Wesley, 1991).
  10. F. Vollmer, D. Braun, A. Libchaber, M. Khoshsima, I. Teraoka, and S. Arnold, “Protein detection by optical shift of a resonant microcavity,” Appl. Phys. Lett.80, 4057–4059 (2002). [CrossRef]
  11. A. Armani, D. Armani, B. Min, K. Vahala, and S. Spillane, “Ultra-high-Q microcavity operation in H2O and D2O,” Appl. Phys. Lett.87(2005). [CrossRef]
  12. N. Hanumegowda, C. Stica, B. Patel, I. White, and X. Fan, “Refractometric sensors based on microsphere resonators,” Appl. Phys. Lett.87(2005). [CrossRef]
  13. M. I. Cheema, “Towards optimal whispering gallery mode microcavity sensors: Novel techniques and analyses,” Ph.D. thesis, McGill University (2013). (To be published).
  14. M. I. Cheema and A. G. Kirk, “Accurate determination of the quality factor and tunneling distance of axisymmetric resonators for biosensing applications,” Opt. Express21, 8724–8735 (2013). [CrossRef] [PubMed]
  15. T. Lu, H. Lee, T. Chen, S. Herchak, J.-H. Kim, S. E. Fraser, R. C. Flagan, and K. Vahala, “High sensitivity nanoparticle detection using optical microcavities,” PNAS108, 5976–5979 (2011). [CrossRef] [PubMed]
  16. A. Oraevsky, “Whispering-gallery waves,” Quantum Electron.32, 377–400 (2002). [CrossRef]
  17. S. Arnold, M. Khoshsima, I. Teraoka, S. Holler, and F. Vollmer, “Shift of whispering-gallery modes in micro-spheres by protein adsorption,” Opt. Lett.28, 272–274 (2003). [CrossRef] [PubMed]
  18. I. M. White and X. Fan, “On the performance quantification of resonant refractive index sensors,” Opt. Express16, 1020–1028 (2008). [CrossRef] [PubMed]
  19. J. Hu, X. Sun, A. Agarwal, and L. C. Kimerling, “Design guidelines for optical resonator biochemical sensors,” J. Opt. Soc. Am. B26, 1032–1041 (2009). [CrossRef]
  20. J. Homola, I. Koudela, and S. S. Yee, “Surface plasmon resonance sensors based on diffraction gratings and prism couplers: sensitivity comparison,” Sensors and Actuators B: Chemical54, 16–24 (1999). [CrossRef]
  21. I. White, H. Oveys, and X. Fan, “Liquid-core optical ring-resonator sensors,” Opt. Lett.31, 1319–1321 (2006). [CrossRef] [PubMed]

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