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Enhanced optical trapping via structured scattering


Interferometry can completely redirect light, providing the potential for strong and controllable optical forces. However, small particles do not naturally act like interferometric beamsplitters and the optical scattering from them is not generally thought to allow efficient interference. Instead, optical trapping is typically achieved via deflection of the incident field. Here, we show that a suitably structured incident field can achieve beamsplitter-like interactions with scattering particles. The resulting trap offers order-of-magnitude higher stiffness than the usual Gaussian trap in one axis, even when constrained to phase-only structuring. We demonstrate trapping of 3.5–10.0 μm silica spheres, achieving a stiffness up to 27.5 ± 4.1 times higher than was possible using Gaussian traps as well as a two-orders-of-magnitude higher measured signal-to-noise ratio. These results are highly relevant to many applications, including cellular manipulation1,2, fluid dynamics3,4, micro-robotics5 and tests of fundamental physics6,7.

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Figure 1: Trapping via Mie interference.
Figure 2: Trap stiffness of ENTRAPS.
Figure 3: Layout of experiment.


  1. Thalhammer, G., Steiger, R., Bernet, S. & Ritsch-Marte, M. Optical macro-tweezers: trapping of highly motile micro-organisms. J. Opt. 13, 044024 (2011).

    Article  ADS  Google Scholar 

  2. Bowman, R. et al. Position clamping in a holographic counterpropagating optical trap. Opt. Express 19, 9908–9914 (2011).

    Article  ADS  Google Scholar 

  3. Franosch, T. et al. Resonances arising from hydrodynamic memory in Brownian motion. Nature 478, 85–88 (2011).

    Article  ADS  Google Scholar 

  4. Jannasch, A., Mahamdeh, M. & Schäffer, E. Inertial effects of a small Brownian particle cause a colored power spectral density of thermal noise. Phys. Rev. Lett. 107, 228301 (2011).

    Article  ADS  Google Scholar 

  5. Palima, D. & Glückstad, J. Gearing up for optical microrobotics: micromanipulation and actuation of synthetic microstructures by optical forces. Laser Photon. Rev. 7, 478–494 (2012).

    Article  ADS  Google Scholar 

  6. Kheifets, S., Simha, A., Melin, K., Li, T. & Raizen, M. G. Observation of Brownian motion in liquids at short times: instantaneous velocity and memory loss. Science 343, 1493–1496 (2014).

    Article  ADS  Google Scholar 

  7. Li, T., Kheifets, S., & Raizen, M. G. Millikelvin cooling of an optically trapped microsphere in vacuum. Nature Phys. 7, 527–530 (2011).

    Article  ADS  Google Scholar 

  8. Jannasch, A., Demirörs, A. F., van Oostrum, P. D. J., van Blaaderen, A. & Schäffer, E. Nanonewton optical force trap employing anti-reflection coated, high-refractive-index titania microspheres. Nature Photon. 6, 469–473 (2012).

    Article  ADS  Google Scholar 

  9. Katz, O., Small, E., & Silberberg, Y. Looking around corners and through thin turbid layers in real time with scattered incoherent light. Nature Photon. 6, 549–553 (2012).

    Article  ADS  Google Scholar 

  10. Mitchem, L. & Reid, J. P. Optical manipulation and characterisation of aerosol particles using a single-beam gradient force optical trap. Chem. Soc. Rev. 37, 756–769 (2008).

    Article  Google Scholar 

  11. Baumgartl, J., Mazilu, M. & Dholakia, K. Optically mediated particle clearing using Airy wavepackets. Nature Photon. 2, 675–678 (2008).

    Article  ADS  Google Scholar 

  12. Chen, J., Ng, J., Lin, Z. & Chan, C. T. Optical pulling force. Nature Photon. 5, 531–534 (2011).

    Article  ADS  Google Scholar 

  13. Brzobohatý, O. et al. Experimental demonstration of optical transport, sorting and self-arrangement using a ‘tractor beam’. Nature Photon. 7, 123–127 (2013).

    Article  ADS  Google Scholar 

  14. Hakobyan, D. & Brasselet, E. Left-handed optical radiation torque. Nature Photon. 8, 610–614 (2014).

    Article  ADS  Google Scholar 

  15. Ashkin, A. Forces of a single-beam gradient laser trap on a dielectric sphere in the ray optics regime. Biophys. J. 61, 569–582 (1992).

    Article  Google Scholar 

  16. O'Neil, A. T. & Padgett, M. J. Axial and lateral trapping efficiency of Laguerre–Gaussian modes in inverted optical tweezers. Opt. Commun. 193, 45–50 (2001).

    Article  ADS  Google Scholar 

  17. Nieminen, T. A., Heckenberg, N. R. & Rubinsztein-Dunlop, H. Forces in optical tweezers with radially and azimuthally polarized trapping beams. Opt. Lett. 33, 122–124 (2008).

    Article  ADS  Google Scholar 

  18. Kozawa, Y. & Sato, S. Optical trapping of micrometer-sized dielectric particles by cylindrical vector beams. Opt. Express 18, 10828–10833 (2010).

    Article  ADS  Google Scholar 

  19. Stilgoe, A. B., Nieminen, T. A., Knöener, G., Heckenberg, N. R. & Rubinsztein-Dunlop, H. The effect of Mie resonances on trapping in optical tweezers. Opt. Express 16, 15039–15051 (2008).

    Article  ADS  Google Scholar 

  20. Palima, D. et al. Optical forces through guided light deflections. Opt. Express 21, 581–593 (2013).

    Article  ADS  Google Scholar 

  21. Bowman, R. W. & Padgett, M. J. Optical trapping and binding. Rep. Prog. Phys. 76, 026401 (2013).

    Article  ADS  Google Scholar 

  22. Moore, D. C., Rider, A. D. & Gratta, G. Search for millicharged particles using optically levitated microspheres. Phys. Rev. Lett. 113, 251801 (2014).

    Article  ADS  Google Scholar 

  23. Geraci, A. A., Papp, S. B. & Kitching, J. Short-range force detection using optically cooled levitated microspheres. Phys. Rev. Lett. 105, 101101 (2010).

    Article  ADS  Google Scholar 

  24. Huang, R. et al. Direct observation of the full transition from ballistic to diffusive Brownian motion in a liquid. Nature Phys. 7, 576–580 (2011).

    Article  ADS  Google Scholar 

  25. Ye, Z. & Sitti, M. Dynamic trapping and two-dimensional transport of swimming microorganisms using a rotating magnetic microrobot. Lab Chip 14, 2177–2182 (2014).

    Article  Google Scholar 

  26. Nieminen, T. A. et al. Optical tweezers computational toolbox. J. Opt. A 9, S196–S203 (2007).

    Article  ADS  Google Scholar 

  27. Mazilu, M., Baumgartl, J., Kosmeier, S. & Dholakia, K. Optical eigenmodes; exploiting the quadratic nature of the energy flux and of scattering interactions. Opt. Express 19, 933–945 (2011).

    Article  ADS  Google Scholar 

  28. Mazilu, M. & Dholakia, K. Resonance enhanced optical manipulation: the push and pull of light. Proc. SPIE 8458, 845809 (2012).

    Article  Google Scholar 

  29. Farré, A., Marsà, F. & Montes-Usategui, M. Optimized back-focal-plane interferometry directly measures forces of optically trapped particles. Opt. Express 20, 12270–12291 (2012).

    Article  ADS  Google Scholar 

  30. Tay, J. W., Taylor, M. A. & Bowen, W. P. Sagnac-interferometer-based characterization of spatial light modulators. Appl. Opt. 48, 2236–2242 (2009).

    Article  ADS  Google Scholar 

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This work was supported by the Australian Research Council Discovery Project (contract no. DP140100734) and by the Air Force Office of Scientific Research (grant no. FA2386-14-1-4046). W.P.B. acknowledges support through the Australian Research Council Future Fellowship scheme FF140100650.

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Authors and Affiliations



M.A.T. and W.P.B. conceived and led the project. M.A.T. developed the theoretical concepts and performed the calculations and analysis. A.B.S. and H.R.D. developed the experimental apparatus. M.W. and M.A.T. performed the experiments, with assistance from A.B.S. M.A.T. and W.P.B. wrote the paper with input from all co-authors.

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Correspondence to Michael A. Taylor.

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The authors declare no competing financial interests.

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Taylor, M., Waleed, M., Stilgoe, A. et al. Enhanced optical trapping via structured scattering. Nature Photon 9, 669–673 (2015).

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