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Ultrasensitive plano-concave optical microresonators for ultrasound sensing


Highly sensitive broadband ultrasound detectors are needed to expand the capabilities of biomedical ultrasound, photoacoustic imaging and industrial ultrasonic non-destructive testing techniques. Here, a generic optical ultrasound sensing concept based on a novel plano-concave polymer microresonator is described. This achieves strong optical confinement (Q-factors > 105) resulting in very high sensitivity with excellent broadband acoustic frequency response and wide directivity. The concept is highly scalable in terms of bandwidth and sensitivity. To illustrate this, a family of microresonator sensors with broadband acoustic responses up to 40 MHz and noise-equivalent pressures as low as 1.6 mPa per √Hz have been fabricated and comprehensively characterized in terms of their acoustic performance. In addition, their practical application to high-resolution photoacoustic and ultrasound imaging is demonstrated. The favourable acoustic performance and design flexibility of the technology offers new opportunities to advance biomedical and industrial ultrasound-based techniques.

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Fig. 1: Plano-concave optical microresonator ultrasound sensor.
Fig. 2: Plano-concave microresonator sensor sensitivity.
Fig. 3: Acoustic frequency response and directivity.
Fig. 4: Optical fibre microresonator sensor.
Fig. 5: Imaging demonstrations.


  1. Beard, P. Biomedical photoacoustic imaging. Interface Focus 1, 602–631 (2011).

    Article  Google Scholar 

  2. Wang, L. V. & Gao, L. Photoacoustic microscopy and computed tomography: from bench to bedside. Annu. Rev. Biomed. Eng. 16, 155–185 (2014).

    Article  Google Scholar 

  3. Powers, J. & Kremkau, F. Medical ultrasound systems. Interface Focus 1, 477–489 (2011).

    Article  Google Scholar 

  4. Drinkwater, B. W. & Wilcox, P. D. Ultrasonic arrays for non-destructive evaluation: a review. NDT E Int. 39, 525–541 (2006).

    Article  Google Scholar 

  5. Fischer, B. Optical microphone hears ultrasound. Nat. Photon. 10, 356–358 (2016).

    Article  ADS  Google Scholar 

  6. Grosse, C. U. & Ohtsu, M. (eds) Acoustic Emission Testing (Springer Science & Business Media, Berlin, 2008).

  7. Zhang, E., Laufer, J. & Beard, P. Backward-mode multiwavelength photoacoustic scanner using a planar Fabry-Perot polymer film ultrasound sensor for high-resolution three-dimensional imaging of biological tissues. Appl. Opt. 47, 561–577 (2008).

    Article  ADS  Google Scholar 

  8. Nuster, R., Slezak, P. & Paltauf, G. High resolution three-dimensional photoacoutic tomography with CCD-camera based ultrasound detection. Biomed. Opt. Express 5, 2635 (2014).

    Article  Google Scholar 

  9. Rosenthal, A., Razansky, D. & Ntziachristos, V. High-sensitivity compact ultrasonic detector based on a pi-phase-shifted fiber Bragg grating. Opt. Lett. 36, 1833–1835 (2011).

    Article  ADS  Google Scholar 

  10. Tadayon, M. A., Baylor, M. & Ashkenazi, S. Polymer waveguide Fabry-Perot resonator for high-frequency ultrasound detection. IEEE Trans. Ultrason. Ferroelectr. Freq. Control 61, 2132–2138 (2014).

    Article  Google Scholar 

  11. Preisser, S. et al. All-optical highly sensitive akinetic sensor for ultrasound detection and photoacoustic imaging. Biomed. Opt. Express 7, 4171 (2016).

    Article  Google Scholar 

  12. Hajireza, P., Krause, K., Brett, M. & Zemp, R. Glancing angle deposited nanostructured film Fabry-Perot etalons for optical detection of ultrasound. Opt. Express 21, 6391–400 (2013).

    Article  ADS  Google Scholar 

  13. Yakovlev, V. V. et al. Ultrasensitive non-resonant detection of ultrasound with plasmonic metamaterials. Adv. Mater. 25, 2351–2356 (2013).

    Article  Google Scholar 

  14. Ling, T., Chen, S.-L. & Guo, L. J. High-sensitivity and wide-directivity ultrasound detection using high Q polymer microring resonators. Appl. Phys. Lett. 98, 204103 (2011).

    Article  ADS  Google Scholar 

  15. Li, H., Dong, B., Zhang, Z., Zhang, H. F. & Sun, C. A transparent broadband ultrasonic detector based on an optical micro-ring resonator for photoacoustic microscopy. Sci. Rep. 4, 4496 (2014).

    Article  ADS  Google Scholar 

  16. Paltauf, G., Nuster, R., Haltmeier, M. & Burgholzer, P. Photoacoustic tomography using a Mach-Zehnder interferometer as an acoustic line detector. Appl. Opt. 46, 3352–3358 (2007).

    Article  ADS  MATH  Google Scholar 

  17. Hurrell, A. & Beard, P. C. in Ultrasonic Transducers: Materials and Design for Sensors, Actuators and Medical Applications (ed. Nakamura, K.) Ch. 19, 619–676 (Series in Electronic and Optical Materials 29, Woodhead, Cambridge, 2012).

  18. Zhang, E. Z. & Beard, P. C. A miniature all-optical photoacoustic imaging probe. in Proc. of SPIE Photons Plus Ultrasound: Imaging and Sensing (eds Oraevsky, A. A. & Wang, L. V.) 7899, 78991F-1–78991F-6 (SPIE, San Francisco, 2011).

  19. Varu, H. The Optical Modelling and Design of Fabry Perot Interferometer Sensors for Ultrasound Detection. PhD Thesis, Univ. Coll. London (2014).

  20. Jathoul, A. P. et al. Deep in vivo photoacoustic imaging of mammalian tissues using a tyrosinase-based genetic reporter. Nat. Photon. 9, 239–246 (2015).

    ADS  Google Scholar 

  21. Xia, W. et al. An optimized ultrasound detector for photoacoustic breast tomography. Med. Phys. 40, 32901 (2013).

    Article  Google Scholar 

  22. Beard, P. C., Perennes, F. & Mills, T. N. Transduction mechanisms of the Fabry-Perot polymer film sensing concept for wideband ultrasound detection. IEEE Trans. Ultrason. Ferroelectr. Freq. Control 46, 1575–1582 (1999).

    Article  Google Scholar 

  23. Allen, T. J. & Beard, P. C. Optimising the detection parameters for deep-tissue photoacoustic imaging. In Proc. of SPIE Photons Plus Ultrasound: Imaging and Sensing (eds Oraevsky, A. A. & Wang, L. V.) 8223, 82230P (SPIE, San Francisco, 2012).

  24. Guggenheim, J. A., Li, J., Zhang, E. Z. & Beard, P. C. Frequency response and directivity of highly sensitive optical microresonator detectors for photoacoustic imaging. In Proc. of SPIE Photons Plus Ultrasound: Imaging and Sensing (eds Oraevsky, A. A. & Wang, L. V.) 9323, 93231C (SPIE, San Francisco, 2015).

  25. Zhang, E. Z. & Beard, P. C. Characteristics of optimized fibre-optic ultrasound receivers for minimally invasive photoacoustic detection. In Proc. of SPIE Photons Plus Ultrasound: Imaging and Sensing (eds Oraevsky, A. A. & Wang, L. V.) 9323, 932311-1–9 (SPIE, San Francisco, 2015).

  26. Hu, S., Maslov, K. & Wang, L. V. Second-generation optical-resolution photoacoustic microscopy with improved sensitivity and speed. Opt. Lett. 36, 1134–1136 (2011).

    Article  ADS  Google Scholar 

  27. Allen, T. J., Zhang, E. & Beard, P. C. Large-field-of-view laser-scanning OR-PAM using a fibre optic sensor. In Proc. of SPIE Photons Plus Ultrasound: Imaging and Sensing (eds Oraevsky, A. A. & Wang, L. V.) 9323, 93230Z (SPIE, San Francisco, 2015).

  28. Yao, J. & Wang, L. V. Photoacoustic microscopy. Laser Photon. Rev. 7, 758–778 (2013).

    Article  Google Scholar 

  29. Xie, Z., Jiao, S., Zhang, H. F. & Puliafito, C. A. Laser-scanning optical-resolution photoacoustic microscopy. Opt. Lett. 34, 1771–1773 (2009).

    Article  ADS  Google Scholar 

  30. Treeby, B. E. & Cox, B. T. k-Wave: MATLAB toolbox for the simulation and reconstruction of photoacoustic wave fields. J. Biomed. Opt. 15, 21314 (2010).

    Article  Google Scholar 

  31. Ottevaere, H. et al. Comparing glass and plastic refractive microlenses fabricated with different technologies. J. Opt. A Pure Appl. Opt. 8, S407–S429 (2006).

    Article  Google Scholar 

  32. Yuan, Y. & Lee, T. R. in Surface Science Techniques (eds Bracco, G. & Holst, B.) 51, 3–34 (Springer-Verlag, 2013).

  33. Colchester, R. J. et al. Broadband miniature optical ultrasound probe for high resolution vascular tissue imaging. Biomed. Opt. Express 6, 1502–1511 (2015).

    Article  Google Scholar 

  34. Noimark, S. et al. Carbon-nanotube–PDMS composite coatings on optical fibers for all-optical ultrasound imaging. Adv. Funct. Mater. 26, 8390–8396 (2016).

    Article  Google Scholar 

  35. Bacon, D. Characteristics of a PVDF membrane hydrophone for use in the range 1-100 MHz. IEEE Trans. sonics Ultrason. SU-29, 18–25 (1982).

    Article  Google Scholar 

  36. Yao, J. et al. Wide-field fast-scanning photoacoustic microscopy based on a water-immersible MEMS scanning mirror. J. Biomed. Opt. 17, 80505 (2012).

    Article  Google Scholar 

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This work was supported by the Engineering and Physical Sciences Research Council (EPSRC), the European Union project FAMOS (FP7 ICT, Contract 317744), a Ramsay Trust Memorial Fellowship, the European Research Council through European Starting Grant 310970 MOPHIM, an Innovative Engineering for Health award by the Wellcome Trust (WT101957) and King’s College London and University College London Comprehensive Cancer Imaging Centre, Cancer Research UK and Engineering and Physical Sciences Research Council, in association with the Medical Research Council and Department of Health, UK.

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J.A.G. and P.C.B. wrote the paper. J.A.G. and E.Z.Z. fabricated the sensors. J.A.G., E.Z.Z., I.P., J.L. and P.C.B. developed the fabrication process. J.A.G. and E.Z.Z. performed the sensor characterisations. J.A.G., J.L., E.Z.Z. and P.C.B. developed the characterization methods. T.J.A. and O.O. performed ORPAM experiments. T.J.A., O.O., E.Z.Z. and P.C.B. designed the ORPAM experiments. T.J.A. and J.A.G. analysed the ORPAM data. S.N. and R.J.C. performed the pulse-echo experiment. S.N., R.J.C., E.Z.Z. and A.E.D. designed the pulse-echo experiment. S.N., R.J.C., I.P.P. and A.E.D. developed the ultrasound source used in the pulse-echo experiment. J.A.G. performed tomographic photoacoustic imaging experiments. J.A.G., E.Z.Z. and P.C.B. designed the tomographic imaging experiments. E.Z.Z. and P.C.B. originally conceived the microresonator sensor concept.

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Correspondence to Paul C. Beard.

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Guggenheim, J.A., Li, J., Allen, T.J. et al. Ultrasensitive plano-concave optical microresonators for ultrasound sensing. Nature Photon 11, 714–719 (2017).

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