Following the Keplerian idea of optical forces, one would intuitively expect that an object illuminated by sunlight radiation or a laser beam will be accelerated along the direction of photon flow. Recent theoretical studies1,2,3,4,5 have shown that small particles can be pulled by light beams against the photon stream, even in beams with uniform optical intensity along the propagation axis. Here, we present a geometry to generate such a ‘tractor beam’, and experimentally demonstrate its functionality using spherical microparticles of various sizes, as well as its enhancement with optically self-arranged structures of microparticles. In addition to the pulling of the particles, we also demonstrate that their two-dimensional motion and one-dimensional sorting may be controlled conveniently by rotation of the polarization of the linearly polarized incident beam. The relative simplicity of this geometry could serve to encourage its widespread application, and ongoing investigations will broaden the understanding of the light–matter interaction through studies combining more interacting micro-objects with various properties.
Subscribe to Journal
Get full journal access for 1 year
only $15.58 per issue
All prices are NET prices.
VAT will be added later in the checkout.
Rent or Buy article
Get time limited or full article access on ReadCube.
All prices are NET prices.
Lee, S-H., Roichman, Y. & Grier, D. Optical solenoid beams. Opt. Express 18, 6988–6993 (2010).
Chen, J., Ng, J., Lin, Z. & Chan, C. T. Optical pulling force. Nature Photon. 5, 531–534 (2011).
Novitsky, A., Qiu, C-W. & Wang, H. Single gradientless light beam drags particles as tractor beams. Phys. Rev. Lett. 107, 203601 (2011).
Sukhov, S. & Dogariu, A. Negative nonconservative forces: optical ‘tractor beams’ for arbitrary objects. Phys. Rev. Lett. 107, 203602 (2011).
Saenz, J. Laser tractor beams. Nature Photon. 5, 514–515 (2011).
Sukhov, S. & Dogariu, A. On the concept of ‘tractor beams’. Opt. Lett. 35, 3847–3849 (2010).
Ashkin, A., Dziedzic, J. M., Bjorkholm, J. E. & Chu, S. Observation of a single-beam gradient force optical trap for dielectric particles. Opt. Lett. 11, 288–290 (1986).
Fazal, F. M. & Block, S. M. Optical tweezers study life under tension. Nature Photon. 5, 318–321 (2011).
Padgett, M. & Bowman, R. Tweezers with a twist. Nature Photon. 5, 343–348 (2011).
Dholakia, K. & Čižmár, T. Shaping the future of manipulation. Nature Photon. 5, 335–342 (2011).
Juan, M. L., Righini, M. & Quidant, R. Plasmon nano-optical tweezers. Nature Photon. 5, 349–356 (2011).
Čižmár, T., Garcés-Chávez, V., Dholakia, K. & Zemánek, P. Optical conveyor belt for delivery of submicron objects. Appl. Phys. Lett. 86, 174101 (2005).
Čižmár, T., Kollárová, V., Bouchal, Z. & Zemánek, P. Sub-micron particle organization by self-imaging of non-diffracting beams. New. J. Phys. 8, 1–23 (2006).
Ruffner, D. B. & Grier, D. G. Optical conveyors: a class of active tractor beams. Phys. Rev. Lett. 109, 163903 (2012).
Chiou, A. E., Wang, W., Sonek, G. J., Hong, J. & Berns, M. W. Interferometric optical tweezers. Opt. Commun. 133, 7–10 (1997).
Mizrahi, A. & Fainman, Y. Negative radiation pressure on gain medium structures. Opt. Lett. 35, 3405–3407 (2010).
Grover, A., Swartzlander, J., Peterson, T. J., Artusio-Glimpse, A. B. & Raisanen, A. D. Stable optical lift. Nature Photon. 5, 48–51 (2011).
Brzobohatý, O. et al. Experimental and theoretical determination of optical binding forces. Opt. Express 18, 25389–25402 (2010).
Demergis, V. & Florin, E-L. Ultrastrong optical binding of metallic nanoparticles. Nano Lett. 12, 5756–5760 (2012).
MacDonald, M. P., Spalding, G. C. & Dholakia, K. Microfluidic sorting in an optical lattice. Nature 426, 421–424 (2003).
Dholakia, K., MacDonald, M. P., Zemánek, P. & Čižmár, T. Cellular and colloidal separation using optical forces. Methods Cell Biol. 82, 467–495 (2007).
Burns, M. M., Fournier, J-M. & Golovchenko, J. A. Optical matter: crystallization and binding in intense optical fields. Science 249, 749–754 (1990).
Dholakia, K. & Zemánek, P. Gripped by light: optical binding. Rev. Mod. Phys. 82, 1767–1791 (2010).
Marston, P. L. Axial radiation force of a Bessel beam on a sphere and direction reversal of the force. J. Acoust. Soc. Am. 120, 3518–3524 (2006).
Mitri, F. Negative axial radiation force on a fluid and elastic spheres illuminated by a high-order Bessel beam of progressive waves. J. Phys. A 42, 245202 (2009).
Zhang, L. & Marston, P. L. Geometrical interpretation of negative radiation forces of acoustical Bessel beams on spheres. Phys. Rev. E 84, 035601 (2011).
Barton, J. P., Alexander, D. R. & Schaub, S. A. Theoretical determination of net radiation force and torque for a spherical particle illuminated by a focused laser beam. J. Appl. Phys. 66, 4594–4602 (1989).
Gouesbet, G., Lock, J. & Grehan, G. Generalized Lorenz–Mie theories and description of electromagnetic arbitrary shaped beams: localized approximations and localized beam models, a review. J. Quant. Spectr. Rad. Transf. 112, 1–27 (2011).
Draine, B. The discrete-dipole approximation and its application to interstellar graphite grains. Astrophys. J. 333, 848–872 (1988).
The authors acknowledge the comments of H.I.C. Dalgarno and support from the USTAN and the following projects: CSF (GA202/09/0348, GPP205/11/P294), MEYS CR (LH12018), ISI (RVO:68081731), COST-STSM-MP0604-04235 and EC (ALISI CZ.1.05/2.1.00/01.0017).
The authors declare no competing financial interests.
About this article
Cite this article
Brzobohatý, O., Karásek, V., Šiler, M. et al. Experimental demonstration of optical transport, sorting and self-arrangement using a ‘tractor beam’. Nature Photon 7, 123–127 (2013) doi:10.1038/nphoton.2012.332
AIP Advances (2020)
Plasma Physics and Controlled Fusion (2020)
Physical Review A (2019)
Physical Review A (2019)
physica status solidi (a) (2019)