Suchergebnisse

Optical forces allow manipulation of small particles and control of nanophotonic structures with light beams. While some techniques rely on structured light to move particles using field intensity gradients, acting locally, other optical forces can push particles on a wide area of illumination but only in the direction of light propagation. Here we show that spin orbit coupling, when the spin of the incident circularly polarized light is converted into lateral electromagnetic momentum, leads to a lateral optical force acting on particles placed above a substrate, associated with a recoil mechanical force. This counterintuitive force acts in a direction in which the illumination has neither a field gradient nor propagation. The force direction is switchable with the polarization of uniform, plane wave illumination, and its magnitude is comparable to other optical forces. ; This work has been supported, in part, by EPSRC (UK). A.V.Z. acknowledges support from the Royal Society and the Wolfson Foundation. N.E. acknowledges partial support from the US Office of Naval Research Multidisciplinary University Research Initiative Grant No. N00014-10-1-0942. A.M. acknowledges support from the Spanish Government (contract Nos TEC2011-28664-C02-02 and TEC2014-51902-C2-1-R). ; Rodríguez Fortuño, FJ.; Engheta, N.; Martínez Abietar, AJ.; Zayats, AV. (2015). Lateral forces on circularly polarizable particles near a surface. Nature Communications. 6(8799):1-7. https://doi.org/10.1038/ncomms9799 ; S ; 1 ; 7 ; 6 ; 8799 ; Novotny, L. & Hecht, B. Principles of Nano-Optics Cambridge University Press (2011). ; Jackson, J. D. Classical Electrodynamics Wiley (1998). ; Ashkin, A. & Dziedzic, J. M. Optical levitation by radiation pressure. Appl. Phys. Lett. 19, 283 (1971). ; Ashkin, A. Acceleration and trapping of particles by radiation pressure. Phys. Rev. Lett. 24, 156–159 (1970). ; Omori, R., Kobayashi, T. & Suzuki, A. Observation of a single-beam gradient-force optical trap for dielectric particles in air. Opt. Lett. 22, ...

We experimentally demonstrate a low-loss multilayered metamaterial exhibiting a double-negative refractive index in the visible spectral range. To this end, we exploit a second-order magnetic resonance of the so-called fishnet structure. The low-loss nature of the employed magnetic resonance, together with the effect of the interacting adjacent layers, results in a figure of merit as high as 3.34. A wide spectral range of negative index is achieved, covering the wavelength region between 620 and 806 nm with only two different designs. © 2011 American Physical Society. ; Financial support by the Spanish MICINN (Contracts No. CSD2008-00066 and No. TEC2008-06871-C02) and by the Valencian government (Contract No. PROMETEO-2010-087) is acknowledged. C.G.-M. acknowledges financial support from Grant FPU of MICINN. W.D. and A.Z. acknowledge financial support from EPSRC (U.K.). ; García Meca, C.; Hurtado Montañés, J.; Martí Sendra, J.; Martínez Abietar, AJ.; Dickson, W.; Zayats, AV. (2011). Low-Loss multilayered metamaterial exhibiting a negative index of refraction at visible wavelengths. Physical Review Letters. 106(6). https://doi.org/10.1103/PhysRevLett.106.067402 ; S ; 106 ; 6 ; Veselago, V. G. (1968). THE ELECTRODYNAMICS OF SUBSTANCES WITH SIMULTANEOUSLY NEGATIVE VALUES OF $\epsilon$ AND μ. Soviet Physics Uspekhi, 10(4), 509-514. doi:10.1070/pu1968v010n04abeh003699 ; Shelby, R. A. (2001). Experimental Verification of a Negative Index of Refraction. Science, 292(5514), 77-79. doi:10.1126/science.1058847 ; Pendry, J. B. (2000). Negative Refraction Makes a Perfect Lens. Physical Review Letters, 85(18), 3966-3969. doi:10.1103/physrevlett.85.3966 ; Tsakmakidis, K. L., Boardman, A. D., & Hess, O. (2007). 'Trapped rainbow' storage of light in metamaterials. Nature, 450(7168), 397-401. doi:10.1038/nature06285 ; Soukoulis, C. M., Linden, S., & Wegener, M. (2007). PHYSICS: Negative Refractive Index at Optical Wavelengths. Science, 315(5808), 47-49. doi:10.1126/science.1136481 ; Depine, R. A., & Lakhtakia, A. ...

106 6 ; S ; We experimentally demonstrate a low-loss multilayered metamaterial exhibiting a double-negative refractive index in the visible spectral range. To this end, we exploit a second-order magnetic resonance of the so-called fishnet structure. The low-loss nature of the employed magnetic resonance, together with the effect of the interacting adjacent layers, results in a figure of merit as high as 3.34. A wide spectral range of negative index is achieved, covering the wavelength region between 620 and 806 nm with only two different designs. © 2011 American Physical Society. Financial support by the Spanish MICINN (Contracts No. CSD2008-00066 and No. TEC2008-06871-C02) and by the Valencian government (Contract No. PROMETEO-2010-087) is acknowledged. C.G.-M. acknowledges financial support from Grant FPU of MICINN. W.D. and A.Z. acknowledge financial support from EPSRC (U.K.). García Meca, C.; Hurtado Montañés, J.; Martí Sendra, J.; Martínez Abietar, AJ.; Dickson, W.; Zayats, AV. (2011). Low-Loss multilayered metamaterial exhibiting a negative index of refraction at visible wavelengths. Physical Review Letters. 106(6). https://doi.org/10.1103/PhysRevLett.106.067402 Veselago, V. G. (1968). THE ELECTRODYNAMICS OF SUBSTANCES WITH SIMULTANEOUSLY NEGATIVE VALUES OF $\epsilon$ AND μ. Soviet Physics Uspekhi, 10(4), 509-514. doi:10.1070/pu1968v010n04abeh003699 Shelby, R. A. (2001). Experimental Verification of a Negative Index of Refraction. Science, 292(5514), 77-79. doi:10.1126/science.1058847 Pendry, J. B. (2000). Negative Refraction Makes a Perfect Lens. Physical Review Letters, 85(18), 3966-3969. doi:10.1103/physrevlett.85.3966 Tsakmakidis, K. L., Boardman, A. D., & Hess, O. (2007). 'Trapped rainbow' storage of light in metamaterials. Nature, 450(7168), 397-401. doi:10.1038/nature06285 Soukoulis, C. M., Linden, S., & Wegener, M. (2007). PHYSICS: Negative Refractive Index at Optical Wavelengths. Science, 315(5808), 47-49. doi:10.1126/science.1136481 Depine, R. A., & Lakhtakia, A. (2004). A new ...

Wave interference is a fundamental manifestation of the superposition principle with numerous applications. Although in conventional optics, interference occurs between waves undergoing different phase advances during propagation, we show that the vectorial structure of the near field of an emitter is essential for controlling its radiation as it interferes with itself on interaction with a mediating object. We demonstrate that the near-field interference of a circularly polarized dipole results in the unidirectional excitation of guided electromagnetic modes in the near field, with no preferred far-field radiation direction. By mimicking the dipole with a single illuminated slit in a gold film, we measured unidirectional surface-plasmon excitation in a spatially symmetric structure. The surface wave direction is switchable with the polarization. ; This work has been supported in part by the Engineering and Physical Sciences Research Council (grant EP/H000917/2). F.J.R.-F. acknowledges support from grant FPI of Generalitat Valenciana. A. M. acknowledges financial support from the Spanish government (contracts Consolider EMET CSD2008-00066 and TEC2011-28664-C02-02). P. G. acknowledges the Royal Society for a Newton International Fellowship. ; Rodríguez Fortuño, FJ.; Marino, G.; Ginzburg, P.; O'connor, D.; Martínez Abietar, AJ.; Wurtz, GA.; Zayats, AV. (2013). Near-Field Interference for the Unidirectional Excitation of Electromagnetic Guided Modes. Science. 340(6130):328-330. https://doi.org/10.1126/science.1233739 ; S ; 328 ; 330 ; 340 ; 6130 ; Yu, N., Genevet, P., Kats, M. A., Aieta, F., Tetienne, J.-P., Capasso, F., & Gaburro, Z. (2011). Light Propagation with Phase Discontinuities: Generalized Laws of Reflection and Refraction. Science, 334(6054), 333-337. doi:10.1126/science.1210713 ; Ni, X., Emani, N. K., Kildishev, A. V., Boltasseva, A., & Shalaev, V. M. (2011). Broadband Light Bending with Plasmonic Nanoantennas. Science, 335(6067), 427-427. doi:10.1126/science.1214686 ; Merlin, R. (2007). ...